1
National v
Academy
.../“
of
Sciences .
National
Research Council
1
NUCLEAR
SCIENCE
SERIES
The Radiochemistry of Uranium
COMMITTEE
ON
NUCLEAR
RM~~
D.A.Bronrlw, WmIM Yak Un-v
D.Emm, V* Cb8imntr Imtltum ofTtim@v
C.K.Rad.Exauthv-WY Ndod
Mmin J.~ N8tlonal BuruuofSmvictor P.w Brookhawn N8tlrmDI ~ QmUOW R.Ch~h Florlti Sam IArivadty
w.A.PO*U Cdifornin l-m
d Ta=hndtwY
Q.c.Phllllm Rla Uninrdty
Gmfw A.Kdrtmd U.S.Atornk ErwuvCmnrnWm JohnMcElhlnw N#vd~ Labrmwy
SCIENCE
Aarkmv ofSc-
AEC Category’ UC-4
NAS-NS-3050
The Rcdiochemistry
JAMES
of Uranium
E. GINDLER
Argonne National Argonne, Illinois
Laboratory
Issuance Date:March 1962
LIBRARIES PROPERTY
Subcommittee on Radochemistry NationalAcademy of Sciences—National Research Council
. .. ..;,
Price $3.Q whichistheminimum order price for eithar one, twu, or three rendomly mlectad publications in the NAS-NS =ias. Additional individual mpies will be cold in incramentaof three for S3.00. Available from: National Technical Information service U.S. Department of Commarm Springfield, Virginia 22151
The Subcommittee on Radlochemistry Is one of a number of aubcommltteeB working under the Committee on Nuclear Science wlthln the National Academy of Sciences - National Research council . Its members represent government, Industrial, and university laboratories In the areas of nuclear chemistry and analytical chemistry The Subcommittee has concerned ltBelf with those areas of nuclear ec~ence whtch tivolve the chemlBt, Buch as the uollectlon and dlstrlbutlon of radioohemlcal procedures, the establishment of Speolflcatlons for radlochemlcally pure reagent’8, availability of cyclotron time for service irradiations, the place of radlochemlstry in the undergraduate college program, etc. This series of monographs has grown out of the need for up-t~-date compllat~ons of radlochemlcal Information and procedures. The Subcommittee has endeavored to present a series which will be of maximum use to the worktig solentlst and which contatis the latest available Information. Each monograph collecte in one volume the pertinent Information required for radlochemlcal work with an Individual element or a group of closely related elements. An expert in the radiochemistry of the putloular elemerrt has written the monograph, followlng a standard format developed by the Subcommittee. The Atomic Energy Commlsslon has sponsored the prlntlng of the series. The Subcommittee Is confident these publications wI1l be useful not only to the radlochemist but also to the research worker In other fields such as physics, biochemistry or medlclne who wishes to use rad~ochem~cal techniques to solve a specific problem.
W. Wayne Meinke, chairman Subcommittee on Radlochemlstry
iii
INTRODUCTION This volume which deals with the radlochemlstry of uranium Is one of a aerles of monographs on radlochemlstry of the elements. There Is included a review of the nuclear and chetical features of particular Interest to the radlochemlst, a discussion of problems of dissolution of a sample and counting techniques, and finally, a collection of radlochemical procedures for the element as found In the�literature . The series of monographs will cover all elements for which radlochemlcal procedures are pertinent. Plans Include revision of the monograph periodically aa new technlquefl and procedures warrant. The reader Is therefore encouraged to call to the.attention of the author any publlshed or unpublished material on the radiochemlstry of uranium which might be Included In a revised version of the monograph.
Iv
CONTENTS I. II. III . Iv.
General Reviews of’the Inorganlo and Analytiml of Uranium
chemistry 1
General Retiewe of the Radloohemietry of Uranium
3
Table of Isotopes of Urantum
3
Review of Those Features of Uranium Chemistry of Chlei’ IntereBt to the Radloohemiat
5,
A.
Metallic uranium
5
1. ;. .
5 6 6
Preparation PhyOloal propertlea chemical properties
B.
Compound6 of Uranium
c.
The Chemistry of Uranium In Solutlon
14
1. 2. 3.
14 21 30
D.
oxidation states Complex ion formation Non-aqueous solutions of uranium
Separation of Ubanium &
3. 4. 5* 6. 7. ,E.
7
39
Preclpltation Solvent extraction EtherB, eaters, ketones, aridaloohola OrganophoBphorus oompoundo Amines and quaternery _niuiu wilts Carboxylla acids Chelating agents Ion exohange Anion exchange Cation axohange Chromat@raphy Volatilization Eleotroohemical metkds Pyrometallurgical prooesset3
236
Determination of’Uknium 1. .2. 3.
40” 60 63 122 . ’169 100 182 202 204 222 227 231 232 235
236 241 248
Counting teohnique~ S&mple preparation Activation analyei8
v
F.
Dissolution of lJr@nium Samples
252
1. 2. 3.
252 254 254 255 256 256
;: .
v.
Metallio uranium Alloys of uranium Compounde of urantum Mt?teoritea, minerals, and orem Blologloal samples Air dust mmplea
Colleotlon of Detailed ~ooedures
vi
257
The Radiochemistry of Uranium JAMES E. GINDLER Argonne National Labw-story Argonne, Illinois
1.
General Revlewa of the Inorganic and Analytical Chemletry of uranium . 1.
J. W. Mellor,
“Uranium” In “A Comprehensive Treatise on
Inorganic and Theoretical Chemlstw, ” Volume XII, Chapter LXIII, pp. 1-13B, LongmanB Green and Company, London, 1932.
2.
R. J. Meyer and E. Pletach, !TGmellnsHandbuch der Anorg~Iachen Chemle, ” 8th Edition, system No. 55, Verlag Chemle, G.m.b.H., Berlln, 1936.
3.
N. V. Sldgwlck, “Uranium”
In “The Chemical Elements and
Their Compounds, ” pp. 1069-1086, Clarendon Press, Oxford, 1950. 4.
C. J. Rodden and J. C. Warf, “Uranlwn” In “Analytical Chemistry of the Manhattan Project, ” National Nuclear Ener~
Series, Dlvlslon VIII, Volume 1, Chapter 1, pp. 3-
159, c. J. Rodden, Ed., McGraw-Hill Book Co., Inc., New York, 1950. 5.
J. J. Katz and E. Rablnowltz,
‘!~e chemistry of UraniumJ “
National Nuclear Energy Series, Division VIII, Volume 5, McGraw-Hill Book Co., Inc., New York, 1951. 6.
G. T. Seaborg, “The Actlnlde Series” In “Comprehensive Inorganic Chemistry, ” Volume I, Chapter 3, pp. 161-223,
1
M. C. Sneed, J. L. Maynard, and R. C. Braf3ted, Ed. , D. van Nostrand Company, Inc. , New York, “1953. 7.
H. R. Hoekstra and J. J. Katz, “The Chemistry of Uranium” in “The Actinide Elements, ” National Nuclear Energy Series, Dlvlsion 17J,Volume 14A, Chapter 6, pp. 130-188, G. T. Seaborg ad
J. J. Katz, Ed., McGraw-Hill Book Co., Inc.,
New York, 1954,
8.” J. J. Katz and G. T. Seaborg, “The Chen@stry of the Acttilde Elements, “ Chapter V, pp. 94-203, John Wiley and Sons, Inc., New York, 1957. 9.
“Uranium, “ R. Calllat and J. Elston,
Directors, In “Nouveau
Traite de Chemle Min%rale, ” Part I, Volume XV, P. Pascal, Diz?ector, Masson et Cie, Parle, 1960. 10.
G. Meister,
part II, 1961.
“Uranium” In “Rare Metals Handbook, ” Chapter
26, pp. 501.571, C. A. Hampel, Ed., Reinhold Publishing Corp., New York, 1954. 11.
L. Grainger, “Uranium and Thorium, “ George Newnes Limited, London, 1958.
12.
A. N. Holden,
IIfiy~icalMetallurgy of UraniumJ “ Addison-
Wesley Publishing Company, Inc., Reading, Mass., 1958. 13.
“Uranium Ore Processing, ” J. W. Clegg and D. D. Foley, Ed., Addison-Wesley
Publishing Compsmy, Inc., Reading, Mass.,.
1958. 14.
“Uranium” in “Scott!s Standard Methods of Chemical Analysis, “ Volume I, pp. 1017-1027, N. H. Furman, Ed., D. van Nostrand Co., Inc., New York$ 1939.
150
TID-5223, Production and Separation of U233, Collected Papers, Part 1 md
16.
TID-5290, Chemistry of Uraniwn, Collected Papers, Book 1 and &ok
17.
Part 2, L. I. Katzin, Ed., 1952.
2, J. J. Katz and E. Rabinowitz, Ed., 1958.
Q. H. Morrison and H. Frei6er, “Solvent Extraction in Analytical Chemistry, 1!Jo~
Wiley
York, 1957. 2
and
‘onsj
Inc., New
II.
General Revi~s
of the Radlochemlatry of Uranium.
J3. K. Hyde, “Radiochemlcal Separation of the Actlnlde
1.
Elernenta” in “The Actinlde Elements, ” National Nuclear Energy Series,
Dlvlelon IV, Volume 14A, Chapter 15, pp.
542-595, G. T. Seaborg and J. J. Katz, Ed., McGraw-Hill Book Co., Inc., New York, 1954. E. K. Hyde, Papar P/728 “Radlochemlcal Separation
2.
Methods
for the Actinlde Elementsj’Volwne 7, pp. 281-303, Proceedings of the ~nternatlonal Conference
In Geneva,
August, 1955, on the Peaceful Uees of Atomic Energy, United Nations, New York, 1956. III.
Table of Isotopes of Uranlu#
.
Ieotope
Half-Life
Tgpe and Ener of Radlatlon rMev)
Method of Preparation
~227
1.3 mln
a 6.B
Th232(a,9n)
U228
9.3 mln
a (-80@) 6.67
Th232(aJ8n); -27
EC(-20~)
daughter 36 mln PU232
Ec(-aoj%)
Th232(a,7n); Q.lZ
u (-20j#)6.42
daughter 20 min P.z233
u 5.884 (67.2Z)
Th232(u,6n); ’15%
5.813 (32.1%)
daughter 17.7 day pa230 ;
5.658 ( 0.7~)
-67 daughter 9.0
U229
U230
58 mln
20.8 day
hour PU234 U231
4.3 day
EC (99++)
Th232(a,5n);
U(5.5X1O-37) 5.45
Pa231(d,2n);
-
3 x 10-3% daughter 26 min PU235 U232
74 year
a 5.318
(68$4)
Th232(u,4n);
5.261
(32%)
daughter 1.31 day
5.134
(0.32S)
PS232; daughter 2.85 year PU236; U233(n,2n)
Table of Isotopes
of Uranium (Continued)
180tope
Half-Life
~ and Ene of Radiation T Mev)
~233
1.626 yeark
u
x
105
Method of Preparation
4.816 (83.5j?J
daughter 27.0 day
4.773 (14.%)
pa233
4.717 ( 1.67) 4.655 (0.07~) 4.582 (0.04~) u@@J1l)
2.48 x 105 year
a 4.768 (72*) 4.717 (28%)
natural radloactlvlty 0.0056~; daughter 1.175 min Pa234m(UX2); daughter 6.66 hour Pa234(UZ); daughter 86.4 year R238;
@35m
26.5 min
IT
,
u233 (n,7)
daughter 24,36o year Pu239
U235(ACIJ)
U236
7.1 x 108 year
2.39 x 107 year
a 4.559 (6.7%)
natural radioactivity
4.520 (2.7X)
0.720%;
4.370 (25%)
daughter 26.5 tin
4.354 (35*)
u235m; daughter
4.333 (14$)
410 day Np235;
4.318 ( e~)
daughter 23.7 min
4.117 (5.8X)
pa235
a 4.499
51$ daughter 236 ~, Np , daughter 6,580 year Pu240; U235(n,y)
U237
6.75 day
e- 0.248
daughter 11 min pa237 i; 4xl~3$ fi2 1;
daughter
U238(n,2n); 4
U236(n,y)
Table of Isotopee of Uranium (Continued) Isotope
Half-Life
Type and Ener y of Radlalilon ?) Mev
Method of Preparation
u*3*(u1)
4.51 x 109 year
a 4.195
natural radloactlvlty 99.276$
U*39
D- 1.21
23.54 mln
U238(n,y); U238(d,p)
U240
14.1 hour
B- 0.36
daughter -7.6 x 107 year ~244
; 2nd order
neutron capture on U*38 ~ Data concerning half-lives, radiations and branching ratloa, unless otherwlae noted haa been obtained from the “Table of Isotopes” by D. Stromlnger, J. M. Hollander and G. T. Seaborg, Reviewa of Modern Phyaica, &
No. 2,,Part II, April, 1958,
ThIa compila-
tion may be consulted for more complete Information on the Lsotopes and for references to the original literature. ~ Ya. P. Dolmchayev and 1. S. Osipov, Atomnaya Energiya, ~, 73 (1959). ~ J. E. Gindler and R. K. Sjoblom, J. Inorg. Nuclear Chem., @
8
(1959) , ~ The half-life of pa 237 haa been reported recently to be39?3 mln,
15, 664 K. Takahaahl and H, Morinaga, Nuclear Phyalca, —
(1960) .
IV.
Review of Those Features of Uranium Chemistry of Chief Interest to the Radiochemls t. A.
1. Preparation.
Metallic Uranium
Uranium metal may be prepared by several methods:~
the reduction of uranium oxldea with carbon In an arc-meltlng furnace; reduction of uranium oxides with magnealum, aluminum, calcium or calcium hydride; the reduction of uranium halldea with alkali or alkaline-earth metala; electrolytic reductfon of uranium halldea; and the thermal decompoaltlon of uranium Iodide. 5
2. PhyBlcal propertlem. Metalllc uranium exists In three allotropic forma :~’~ the orthorhomblc alpha form, stable below 663°c; tlie%etragonal beta form which exlOts between 663°c and 770”C; and the body-centered cubic form which exlets at higher temperatures
(> 770°c).
as compiled by Grainge#
The physical properties of the metal are given In Table I.
Because of the
method of preparation, impurities may be contained In the Also, a number of the physi-
metal which alter Its properties.
cal characteristics depend upon emisotroplc and structural effects, eg. thermal expansion.
Therefore, if physical proper-
ties are pertinent to an experiment or design, It Is best to determine them Indlvldually for the metal used. The changee wrought In metallic uranium by r~dlatlon and thermal cycling may be considerable.
The results of reactor radla-
tlon on the metal are: dimensional instability, surface roughening and ptipllng, warping, high hardness, extreme brittleness, CraCkB and poroalty, broadened x-ray diffraction llnes, and decreased thermal and electrical conductl’vlty.~ Thermal cycling growth is stillar in many respectfl to that caused by radiation damage. However, differences exist, the fundamental difference being In the mechanism of growth. (The reader Is directed to reference 3 for more detailed discussion of this sub#ect. )
3. Chemical properties. Uranium is a highly reactive, metal. potential of +1.80 volts for the half-cell reaction, U+
A
U +3 + 3e,
places It below beryllium and above hafnlum and aluminum in the electromotive force series.5
The metal forms Intermetalllc
compounds with Al, Be, Bi, Co, Cu, (la,Au, Fe, Pb, Mn, Hg, Nl, Sn, Ge, In, Ir, Pd, Pt, Tl, and Zn;~ solid solutlons with Mo, Ti, Zr, and Nb.~
It reacts at varyhg
temperatures with H2, B, C, S1,”
‘2‘ P, As, 02, S, Se, F2, C12, Br2, 12, H20, HT (&3)’‘2s’ N-H3’ ‘0’ ‘cl(g) N204> cH4, co, c02.
~,~
In air, at room temperature, massive
uranium tarnlahes to form a yellow and. eventually a black oxide 6
coating.
Finely divided powder may burn 6pontaneou01y.
In bolllng
water, massive uranium corrodes slowly with the formation of uranium dioxide and hydrogen.
The reaction products with steam are
uranium oxide and hydride.
The dissolution of uranium metal is
discuBsed in eection IV-F.
Table I.
Physical Properties of Uranium Meta~~
Density (high purity)
19.05 * 0.02 gm/cm3
Density (industrial uranium)
18.85 * 0.20 gm/cm3
Melting point
1.132 * l“c.
Boiling point
3,8113”C.
Heat of fusion Vapor pressure (1,600”c.)
4.7 kcal/mole -4 10 mm
Thermal conductivity (70”C.)
0.071 cal/cm-sec-O,C.
Electrical resistivi@
35 x 106 ohm/cm3
(25°C.)
Mean coefficient of linear
16
X
10-6/%
thermal expansion (random orientation 25-loo”c.) Specific heat (25”C.)
6.65
Enthalpy (25°C.)
1,520 cal/mole
Entropy (25”c,)
12.0 cal/mole~C.
~ L. Grainger, reference 4.
IV-B.
Compounds of Uranium
Uranium combines with moBt elements to form a large number and variety of compounds. “Gmelins Handbuch der Anorganischen ,,6 Chemie, — which surveys the literature through the year 1935, describes several hundred compounds.
Katz and Seabor&
describe
some of the more recently prepared compounds, principally of organic character, such as chelates, alkoxidee, amides, mercaptides, and w-cyclopentadienyl
compounds.
7
The oxidation states of uranium In the combined form vary from II to VI. us.
Divalent uranium compounds reported are UO and
Trivalent uranium compounds are more numerous and Include
the hydrfde, nltrlde, sesqulsulflde, halides and borohydrlde. Uranium (III) sulfate UH(S04)2 has also been reported.–7A large number of tetravalent compounds are knowrvarylng
In
complexity from the oxide and simple binary salts to more complicated organic structures. U(C03)2 “ 4H20 and 2(NH4)2C204
Complex salts such as 3(CN3H6)2C03
●
“ U(C204)2 “ 6H20 form an tipor-
tsmt group of uranium (IV) compounds.
Complex salts are formed
also with hallde, sulflte, sulfate, and phosphate Ions.
Inorganic
compounds of pentavalent uranium are UF5, UC15, UC15 “ SOC12, ~ ~ and UF “ xHF.~ UOC13 has been reported as an inter5 “ ‘C15’ 5 mediate compound in the chlorination of uranium oxides with Ucl
carbon tetrachloride.~ pared.~
Uranium (V) alkoxldes have been pre-
Also, the compounds (C5H6N)2 UOC15 and UOC13 o EtOH
have been reported.~
Hexavalent uranium is represented by
UF6 , UC16, U03, uranates, and uranyl (U02+) 2
compounds.
Uranyl
compounds are the most numerous uranium compounds and vary In type from simple salts to complex organic arrangements.
Complex
salts are formed with halide, Iodate, nitrate, carbonate, cyanide, acetate, oxalate, sulfate, phosphate, arsenate, chromate and vanadate ions.
Triple acetate salts of the form M%11(U02)3(CH3C02)9
“ 6H20,
where M1 Is an alkali metal (Ll, Na, or K) and M1l is a divalent metal (Mg, Nl, Zn, etc.), are used In analytical separations of uranium.
Addition compounds, such as U02(N03)2 “ 2CH3COC4H9,
represent a large number of uranyl compounds. Uranates and peruranates are important In the analytical ohemlstry of uranium. 110 yU03 or XM “ yuo3.
Uranates have the general formula xM>
.
6 10 They may be prepared by different methods.–’—
However, In usual analytical procedures, they are precipitated
8
from a uranyl solution by the addition of a aoluab.lemetal hydroxide, ~40H,
NaOH, Ca(OH)2, etc.
The uranates are Insoluble In
water but dla~olve In acids. Peruranate~
are formed when uranyl aolutiona contalnl~
hydrogen peroxide are made alkaline.
The compodtlon
of the
peruranates depends upon the concentration of the alkali and peroxide. ‘2~2%o
The followlng groupO have been identified:
. XH20, M2U06
“ ‘H20’ ‘6”2013
●
XH20, snd M4U08 - XH20.
The peruranate~ are generally soluble In water. are those of the M2U2010
o XH20 group.
The least soluble
The peruranates are
soluble In dilute mineral acide. Table II hate
a number of uranium compounds together with
their behavior in different solvento.
The compounds li~ted are
primarily binary compounds or simple salt6.
The order in which
they appear Is the order In which they tiy be found In “Gmellns Handbuch der Anorganiichen Chemle. ” ~
Table II.
Uranium Compounds and Their Solvent&
Compo,und
Solvent
‘3
s. HNO (vigorou~), cone. HC104, hot 3 cons. H2S04, a. +H202 1. elk., llq. NH
U02
3 s. HNO , aq. reg., cone. H2S04, S1OW1Y 3 converted to,U(IV)-salts In hot fum. HC1
‘3°8
B. HNO ; heated to redness U sO~ Is only 3 v. al. s. dil. HC1 and H2S04, more s. cone. ~ a., s. hot cone. H2S04; I-LFforms s. U02F2 and 1. UT
4
s. mineral a.
U03
U02-xH2~[U(OH)4” (x-2)H20] s. dil. a. ‘3°8
●
XH20
U03 . 2H20
s. a. ❑
. a., converted to U03-H20 in boiling
H20
9
Table II. - Continued Solvent
Compound U03~H20, [~U04,U02(OH)2] U04
●
S. E., warm COnC. U02(N03)2 Eoln. volubility In ~0:
2H20
s@’&.002
g@l
20” c-.0x6 g/loQ ml,
ml; d. HC1; alk.
hydroxides fomnU03
s. H2J03; 1. conc. HfJl, ~so4
U3N4 U02(N03)2
and B. Pemranatem
●
6~0
~
solublllty in ~0:
()”C.170.3 #looml,
60°C-soluble hall
proportions; a. al.,
ether, acetone, dil. a. u.”h. HClb4, h. HN03, h. H2S04, ~~3
+
mineral a. 1. ~O;
s. fiun.HC104, HN03 + H3M3;
metatheolzed to U(~)-hydroxide
by
heating with NaOH UF ~, U2F9, U4F17
d. H20 f’01’lCB S.
U02F2 ~
~6
B. ~O-vlgorous
reaotlon, CC14, CHC13;
v. s. C&C14; ‘02F2 UC13
0. ~0,
1. ~4
d. alcohol, ether
alcohol; 1. ether, amyl alcohol
s. H20, HC1, glac. acetic a.; i. CC14, CHCl s, acetone, Wridlne
UC14
B. SO,
Ucl
ethyl ben~oate; i. ether, CHC1 , benzene 3 s. H20(d.); abmolute alcohol, ethyl
5
C~OH,
acetone, ethyl acetate,
benzoate, trichloracetlc acid, ethyl acetate, benzonltrite, CS2, SOC12 UC16
d. H20; e. CC14, CHC13
UOC12
s. H20
‘02c12
.0. H20: 180c-320 @m
ml; s. alcohol,
ether s. H20
~ dl- and trl-hydratee
are also Well establlahed.
. 10
Table II. - Continued Compound
Solvent a. H20, acetone, methyl- and ethyl-acetate,
UBr4
pyrldine; 1. ether B. H20
‘J0Br2
s. H20, alcohol, ether
‘02Br2
s. H20
UI
3 U14
s. H20
U02(103)2 o H20
v. al. S. H20: 18°C-a
fOFlll, 0.1049
g/100 ml, @ form, 0.1214 g/LOO ml; cold ppt. S. ~03
and H3P04, i. a.
after previously heating to boiling temp.; s. alk. carbonateO v. difficultly s. cono. HC1, dll. HNO
us
3
+0 aq. reg., cone. HN03
‘2s3
d. Eteam, HNO=; s. hot cone. HC1 > al. s. H 0“ s. dll. a., alcohol, (NH4)2C03;
US2 U02S
2’
1. absolute alcohol
‘02s03
s 4H20
1. H20; s. aq. or alcohollc S02 solution
U(S04)2 “ 9H20
S. dll. H2S04
U(S04)2 o 8H20
hydrolyzes In H20 with aeparat~on of basic sulfate, UOS04 “ 2H20; S. dil. mineral a., acetic a.
U(S04)2 E 4H20
hydrolyzes in H20(d. ); s. dll. H2S04, HC1
UOS04 - 2H20
s. a.
U02S04 . 3H20
S. H20: 15.5”C-20.5
g/100”ml, 100°C-
22.2 g/100 ml; s. mineral a. U02S04 c H20
s. H20
USe2
Ignites with HNO
3; chemlcal ‘roperties
slinllar to US2 U02Se
d. H20; s. cold HC1 - forms U02C12
11
Table II. - Continued Solvent
Compound
and H2Se; reactO violently with KN03 Se is first-formed and is then oxidized U02Se03 - 2H20 UB2
‘“ ‘2°; ‘“ ‘C1 a. aqn reg., HNO
3’ m s. cold HF, cold HC1, HN03, cone. H202,
UB4
reduces cone. H SO 24 i. hot cone, HC1, HF; slowly s. hot COllC.
‘12
H2 S04 U(BH4)4
‘“ ‘2°’ alcohO1 d. H20, dil. HC1, dil. HN03 , dll. H2S04;
“2
reactavigorously with heated cone. a. s. a.
‘02c03 U02(HC02)2
“ H20
s. H20:
15°C-420
g/100 ml; s. methyl
alcohol; al. s. formic a.; 1. et~l alcohol, ether, acetone, CS2, CC14, CHC1=, benzene, petroleum ether J
u02(HC02)2
o U03 o 3H20
less s. H20 than neutral salt; more s. formic a. than neutral salt
U02(CH3C02)2
“ 2H20
s. H20:
15°C-7.694
g/loO ml; v. s.
alcohol; i. ether u(c204)2 . 6H20
‘“ ‘2°’ ‘ii’ a“; ‘“ ‘am cone. HNO
U02C204
“ 3H20
Cone”
HC1 ,
3
s1. s. H20:
14°C-0.8 g/100 ml, 100°C-
3.3 g/100 ml; s. mineral a., H2C204 and alk. oxalate solutlons U(C4H406)2
o 2H20
1. H20, organic solvents; s. tartarlc a., tartrates, cone. a.
U02(C4H406) U02(CNS)2
. 4H20
“ 8H20
s1. s. H20:
17°C-3.28
g/100 ,CC Solutlon
a. H20, ethyl and amyl alcohol, acetone, ether
12
Table II. - COntlnUed Compeund
Solvent
usi2
i. cold or hot cone. : HC1, HN03S H2S04~ aq. reg.; s. cone. ~;
converted to
silicate and uranate by molten alk. and alk. carbonates at red heat d. boiling cone. FINO reg., alk. 3’ aq” hydroxide U(H2P02)4
- fi20
i. H20, dil. H2S04; s. H_N03
U02(H2p02)2 U(HP03)2
i. H20, dil. a.; a. cone. a., 50% ~P02
“ 4H20
‘“ ‘2°’ ’11” a“; ‘“
cone. a., 50~ H PO 33
U02HP03
‘“ ‘2°’ ’11” a“; ‘“ Cone” a“
U3(P04)4
i. H20; attacked by a., esp. IDJ03
IJH2(P04)2 o 2H20
s, cone. HC1
(U02)3(P04)2 “ -20
i, H20, acetic a.; s. mineral a.
U02HP04 o fi20
i. H20; s. mineral a., xs*(m4)2c03 i. H20, cold a.
‘p207 (U02)P207 - 5H20
i. H20, alcohol, ether; s. XS. Na4p207, HN03 i. H20, HC1, HN03S H2S~4
U(P03)4 U02(P03)2 U3AS4
s. HNO
U3(AE04)4
6. HNO
3 3
UH2(AS04)2
“ 3H20
s. HC1
UH2(AS04)2
- 2H20
I. H20; S. dil. a., esp. arsem~c a“
U02HAS04 . 4H20
i. H20, acetic a..
(TJ02)2AS207 5U02 “ 3Sb205 . 15H20 U03
S. aq. reg., hot cone. HC1, d. HNO
~ f120
“ ‘2°5 U03 . V205 o H20 2U0
3 “ ‘2°5 U02Cr04 o xH20
s. H20
13
3
Table II. - Continued Compound
Solvent
U(M004)2
s. HC1
U02M004
1. H20, CHC1s, benzene, toluene, ether, alcohol, acetic a.; s. HC”l, H2SC14, HN03,
‘2s207
3U03 o 7M003
‘“ ‘2°; ‘“ ‘neral ‘“
Uo
“ 3W03 “ 5H20
s. KNo 3 S. HC1; d. I-INo“ 1. H2S04 3’ s. H20
“ W03 - 2H20
al. s. H20
“ 8M003 “ 13H20 3 U02 “ 3W03 “ 6H20 Uo Uo
3 3
Abbrevlatlons u“sed: a.
acid
rum.
alk.
alkali
h.
hot
aq.
aqueous
1.
insoluble
aq. reg.
aqua regla
1.
llquld
cone.
concentrated
a.
soluble
d.
decomposes
al .
Slightly
dll .
dilute
v.
very
esp.
especially
Xs .
excess
Iv-c . 1.
-
fuming
The Chemistry of .Uranium In Solution
Oxidation states.
Four oxldatlon states are known for uranium
ions In aqueous solution: the tri-, tetra-, penta-, and hexaposltive
states.
sented as U‘3, u~,
Ions In these states are usually repreU02+ and UO:2 , respectively.
The
potentials between the various oxldatlon states are given below for acldlc and baslo solutlons. 2 Acldlc solutlon: U=QU+3
1 ~ HC104 at 25°C
=Q
*
-Quo+
~
-Q%9+2 ““
14
Baslo solution: ~
U(OH)3~
U(OH)4~
TrIpoaltive uranium, U+3.
U02(OH)2
Hvldenoe for the existence of
U+3 ccine~ from the rever~lblllty of the U(III)~(IV) Solutions may be prepa~d
couple.
by t?hedissolution of a uranium
trihallde or bg the electrolytlo reduction of a uranium (IV) or (VI) f301utlon. Chloride, bromide, Iodide, perchlorate W
sulf’ate solutions of uranlum(III) have been reported.~
They are deep red ln”color and unstabl~wlth to @4
occurring and hydrogen behg
fied aolutlon~
oxidation of’U+3
evolved.
Strongly acldl-
or those kept at low temperature@
appear
to be more ntable. Tetrapoaltlve uranium, U +4 .
The existence of the U
+4
Ion In solution has been “confirmed by measurement of the acid liberated on dlaaolving UC14 ~
and by solvent extraction
studies of U(IV) with thenoyltrlf’luoroaceton~
and
l’4b Uranoua Bolutlonm may be p=pared acetylacetone .— aolutlon of a water-moluble salt:
by dln-
the chloride, braui~e,
Iodide, or uulf’ate;by .dleaolutloh of uranium or a uranium oompound In an appropriate solvent, e.g., uranium metal In eulfurlc or phosphoric acid; or by reduction of a uranyl eolutlon by chemical, electroohemloal or photochemlcal means. The solutions are green In oolor.
They are aitable In the
abEence of air but are oxldlzed by oxygen.
Uranlum(~)
under-
goes hydrolymta with evidence in the flrnt etagea for the formation of the mononuclear ~pecies, UOH+3. 13’15-18 Polymeric specle8 al~o are formed which apparently are not In equilibrium with the monamer. ~Hlet~e#f’ound
that
in addltlon to the monomeric species, a polymer of the @pe 4U[(OH)3U],n
could account for the hydrolyals of uranium
to good approximation.
Table III, baaed prtirlly
upon the
data ctimplled by Bjerrum, Schwarzenbach, and Slll<n,~
15
Table111.~lynla T
BIedlum
20
V’ar
C(NaC104) 0.5( NUC104) +0
25 10-43 10-43
25 25
o,19(Hclo~) o Oom 3(N8)C104 o Ool-r
25
2(C104-)
15-25 25 gl,
red
001
~02+ qh 2 gl
gl
qh,S1
25-26 20-25 ? 25 15 20 20 20
Q, fD,BP 25?
gl,fp,Bp 25? P(H.f) Bol
0 oorr V.m vu
o mm c[Bn(No3)21 1(M)C104 l(ra)cloq l(Na)C104 O.15(N8C1O4)
0.1clo~ aJo2(C104) +U03 o WIT
Iag
vu
WV ardU%
IanL#
or equtilbrium OOnTtlnt,~a
-2.30 “~ -1.63 (c-2), -1,56(-1), -1.50 (mo.5) ‘~ -1.90(10”), -1. !7(25”), -1. m(43”) ~ -1.12(10”), -0.6s[25”), 4.18(!3”) A*K1- 11.7, A*% - 36(25”) ‘~ -1.3S(15.2”), -1.12(24.7”) A“% = 10.7, A*S1- 33,A% - 52 ●
P2
●E
-2.0, B3;,n+1 -1,2---4n4n
%5
-3.77 [WIJH)4(S)”I
●
o.0347[m(mo, )21 l(Hli)clo4, o,4U07 3@eJcloh, 1.uuoy ‘
qh,@ qh,@
After J. BJermm,
O.
~6 16 17 23
~. 6.04,~%W,
40
\
-4.,4, .“ -4.19
pdyn
Ks3-3-@, KS4-3.77
w 37 9 250 39,52,53 V2 42,cr43 42,ar54 40
40 Wi
opl
50 51 45 46 46
**% - 4“3’‘%= - 4 %12 -3.66, ‘P22-6.02 .,
46 47
“s12- 3-~. ● B22- 6,3,*B43x-12.6 (qh), ●543- 12.9(sl)
47
“Pa,n+l: (n+l)m$+ + =T!X# e U02[(OH)2U021: + =+ ~te. ~
13 22 13,21
lB
~ 4.2, \ -5.20 O.1(M)C1O4 %22 -5.06, ● 1924 -1.26 o Oorr ’522-5..92 0.3 W[BE(C10Q)21 ~ ‘5.40, 0.0347 [MC10*)21 ~ ‘5.82(25”), ‘5.1 O(4O”), A*H1-20.8 “p= -6.15(25”), -5.92(40”), A~22-6.7
Uoy
Fmfemnce 21
-1.6s, & -1.74 ,& + H20# UOH3+ .+H+ & :@+ D20~UO$++D+ ●i32:U4++ 2220# u(oH)fl + 2H+ : (n+l)#+ + 3140# U[(OH)3UI~+] “eJn,n+l + 3nN+ “~ -4.3 %= -5.87 “~ -4.50, %= -4.95 evU02H030H, U02(N03 )30#’~ -4.09 ● P= -5.97 (M.6),-5.72 (C-O.06) ~ -4.70(?, UOOref.43),,.polyn .px ‘Pa,~+~o.30---6,35n 0.30 ---4011II ● %*1 “B22-5.94, 7943-14.29 Ka[U308(OH)~-q : -3.55 (n-0), -6. s(n-1), -7.4( n.=2), .ll.0(11-3), -11.4(1-1=4) %43 -12. go %= -5.943 ev (U020H)~, notU020H+
~
●%
\ 8P dlat gl gl a
of
andL.II. Sfl16n, reference 20. Sahwarzanbaoh.
18
--. –--- ,.
..
-10 0-
0.1 1
MLmo,
l(mclo,)
1(-0,)
l(m)olo,
11
mbla
1.
111
(Osmn!w.i)
tinaa.autiv. .. ■t.p.wlsa awtanbm I K m.
MdM1on of lW
b. #ddition
of
(L)
pmtunutd 1i2m)d (2L)with●llmlultlom
or WOtall
0.
Mdltim or W.atoi-ati
%-IL +‘-
(ml
llgmld
(~L)
[X#] %L
%-
—
[~.lzl[xl
With elmx-atimof Dmtonm
mm+m#n#n+nH+ “Bin. —[H#J m+]” 1MP[2LI”
‘% -
rP#,JILl @
- n)
Othm
n.
mien
L in Fw4romide (oE-), FL 10 -tar mm ‘q u
thenthmid dlmo.aiatlon acmatait rorthah@rvMln of m m-ailic
ion.
Ill
●bmov-lationa
Ued
fa
cam
riv9
m
:
summarizes the remits of the uranium
of several studies on the hydrolyses
Ion.
Pentaposltlve uranium, UO~ . ion in solution has been+confimed 24-26 ments .—
The existence of uranium(V) by polarographic measure-
Support for the U02+ ion comes from the reversi-
bility of the U(V)/’U(VI) coupl& crgEtallographi_
and from infrared=
and
studies of uranium and transuranic ele-
ments.
Solutions of U02+ may be prepared by dissolution of
UC15~
or by reduction of a uranyl solution, electrolytically
or with U(IV) ions, hydrogen, or zinc amalgam. =
me
fo~ation
of u(v) is an intermediate process in the photochemical reduction of U(VI) in a sucrose solution.~
me
~olution~ are unstable
and disproportionate to U(VI) and U(IV).
The rate of dls-
proportionation is second order in uranium(V) and first order in acid concentration. ~ most a’tabie in the pH range of 2 to 4.%
concentration me
U02+ iOn is
It is oxidized to
the ursnyl ion by molecular oxygen, Fe(III) and Ce(IV).~ Hexapositive uranium, UO~2 .
A number of physical-chemi-
cal measurements as well as crystallographic, infrared and Raman spectra studies support the existence of U(VI) ion as ~o+2 .Q Uranyl solutions are easily prepared by dlB2 solution of water-soluble ealts: the nitrate, fluoride, chloride, bbomide, iodide, sulfate, and acetate.
Other water-
soluble uranyl Baits include those of other orgsnic acids: the formate, propionate, butyrate, and valerate; and certain double salts such as potassium uranyl sulfate, sodium uranyl carbonate, sodium uranyl chromate, etc.
Uranyl solutions
may be prepared also by dissolution of a uranium h
compound
an appropriate solvent, by dissolution of a lower valence
uranium compound in an oxidizing medium, or by oxidation of lower valence uranium ions already in solution. solutions are yellow in color. uranium solutions.
Uranyl
They are the moOt stable of
As indicated in preceding paragraphs, the 19
uranyl Ion may be reduced by reducing agent~ chemical or photochemlcal means.
or by electro-
The degree of dlaeoclatlon
of uranyl Oalte In aqueou6 aolutlon varies.
Uranyl perchlorate
whereaa, urarqfl
Ie apparently completely dlaaociated;~
fluorlde 1s undlsaoclated and tenda to form dlmera (ace aectlon on complex Ion formation - IV-C2).~
Hydrolyala of the
uranyl ion haa been the subject of extensive Inveatlgatlon. Conalderable evtdence haa been adduced for the formation of According
polymeric apeciea of the type U02(U03)~+.ti to Sutton,%
formation of polymers beyond the trimer U308
la negligible.
2+
However, the trlmer Itself may undergo
further hydrolyaia with the formation of U308(OH)+, U308(OH)2, and eventually anlonlc apeclea.
40,41
Ahrland,~
In hls
original paper, propased the formation of the monomer U02(OH)+ aO wqll aa polynuclear apeciea.
In a reappralaal of the
work, Arhland, Hietanen, and Slll&@
4
stated that there waa
no certain Indication of mononuclear complexes being formed. Rather, the experimental data waa explalned on the basia that complex lonE of the type U02[(OH)2U02]fl were formed. From the data It waa not poa~lble to dlati~idi
between a
limited mechanism In which n varied from 1 to 3 or 4 or an unlimited mechaniam In which n aasumed all Integral valuea. ~rau& The authors were Incllned to prefer the latter. auggeated that reactlona leadhg
to the formation of polymers
may have a leaa poaitlve value of AH than the reaction leading to the formation of the monomer.
Consequently, the
latter process might be identified more readily at high temperatures than at room temperature.
This la apparently
the case aa was shown by Hearne and Whit&
who determined
the enthalpy change to be 20.8 kcal/mole for the monomeric reaction (U020H+ formed) and 6.7 kcal/mole for the dlmeric reaction (U2052+ formed).
Table III aummarlzea much of the
20
data available on the hydrolyalB of the uranyl Ion,
Included
in the table are values of the equlllbrlum conOtant *K1, the constant for the formation of the monomeric .speclea. This constant has been evaluated by at least seven groups of ~nveBt1gator~25c,38, 42,48-51
46 exclusive or Hearne and Whit%.
The values obtained agree very well (log *K1 = -4.09 to -4.70). However, the experimental condltlonB tlons~
25c,38,50
and assump-
used in some of the evaluations have been
queatloned.~
AlBo, the re-evaluation of Ahrlandl~
already hae been mentioned, and Rydber~
work
has proposed an
explanation for not detecting polynuclear t3peclea In hlB —. experiments.
None-the-leas, one must concur with Rydber&
who wrote, “---it eeems remarkable that the same constants should be obtained for a flctlve mononuclear hydrolyses product with different U(VI) concentrations and so different methods of Investigation---. ”
2.
Complex Ion formation. The ability of uranium to form complex ions In solutlons Is of considerable Importance In Its analytical separation and determination.
Hydrolyses, mentioned In the
previous section, is but a special case of complex ion formation. Numerous complexes have been reported.—34
However, the amount
of quantitative data for the various ligands 1s rather limited and often contradictory. Trlpositive uranium. uranium(III)
cupferrat&
Evidence has been reported for and uranium(III]
~hlor~
Complexes
Tetrapositive uranium. Inorganic complexes of uranium which have been recognized through the formation of complex salts include the fluorlde, chloride, sulfate, sulfite, and phosphate.~ Table IV lists the equilibrium constants and thermodynamic data available for some of the uranium Solutlon.
complexes In aqueous
In addition, a carbonate complex, possibly U(C03)~- ,
has been found to be stable In solutlons of excess carbonate Q or bicarbonate Ions. 21
_lexlng -t
TableIV. Methd
Thiocyanetej
scn-
red
Alnt “
20
10 25
“
40
FhOBphatO,
aol
35
Sulfate, 9of-
diat “
25 n
m
“ *
with u~ Ione- fio~io Ll~c# Sefemnae nealm LOS of equilibrium cmetant, -rkm l(NnC104), 0.6S+~ 1.49,~ 0.46,~ 0.23 57 2(l@)clq, lH+ ~ 1.70,~ 0.52 5 “ ~ 1.49,~ 0.62 5s MI- -10,AS2=9.7 ~- -5.7, Al& -1.8, m q 1.30,~ O.@ 5 ev uA16(SL)~0r UA18(SL)~Var 59
Cm’plex Fmmatlon T
10 25
1ba 1k,ME 60 “ 1$3.24,~ 2.18[~(Eql.125](?) I&a, Of. 60,61 2(@2104,lH+ ‘~ 2.63,“q 1.34 52 n “y 2.52,“~ 1.35 5s
2(HcnoQ) m
“~ 2.53,‘~ -0.13 ‘~ 2.41,‘~ 1.32
M-& -3;2, ~FChlorlde, Cl-
Fluoride,
40
dlm
25 25 25 m
2(wc104), i~ 0.5( N8C104) o mm
10 25 40 25 m
2(Hacloa ), M+ n “
OP “
dint n’ ,, .smlem Srvudde, Sr-
red
0.9sA~= o.7,As2-9.3
n
,1
l[Ne)clo4, 0.6s+
HCl var
lq 0.30
~ 0.52 % %
0.26; or ~ Oae; or q
ev lullOpx h
l(lle)clo~, o.6H+q
O.@,
~
-0.02
4.00,
~
-0.06
H.m
Hcl
0.10
a ‘After
J. ~e-, O. Sohwar;entaoh, andL. O.SU1%I!, mfemnoe 20. COIUIIM onedenotee theowplexjmg ll,gnnd (L). Thenotation Inexphine.i ~ol10NX TableIII. Munerous organlo ocduplexes are formed with the uranlum( IV) Ion:
the acetate, oxalate, tartrate, malate, citrate, lactate,
glyctslate, etc.~
However, the amount of quantitative data
avail able on their formation 10 very meager.
Tishkoff~
has
calculated dlaaoclation conatanta for acetate complexes on the basia of the oxygenated uranium
ion U02+ being formed. The
formation conatanlmmeaaured for acetylacetone, thenoyltrifluoroacetone and ethylenediamhe
tetraacetic acid comp”lexe6 are given
Ln Table V. Pentapoaitlve uranium. Although It appeara that uranium(V) complexes should be foxmscl in the reduction of uranium 22
Ions
in complexlng media, ~
little data 18 available.
Hexaposltlve uranium.
Inorganio uranium
complexes
which have been Idenklfled through the formation of cryatalllne saltm Include the fluorides, chlorideO, nltrateB, sulfateO, ~ carbonate, cyanides, and phoaphate8. Uranyl aolutlone with these anions preOent have been atudled. in Table VI.
The results are listed
A number of dlt3crepanclet3appear In the data.
For
example, evidence for some complexlng of the uranyl ion with 6,77 nltratc 74,76,7T ~ti ch~or1dc67,7 ‘105-10710ns has been reported by
❑
orne lnveBtlgatoru; but a complete lack of evidence hae been
reported by others.~
Day and Power~
have pointed out that the
constanta calculated by them are concentration conetants rather than actlvlty constants. be caused bythe In medium.
Consequently, the small completing effect may
variation of actlvlty coefficients with a change
Other Investigators, however, Who have corrected
their results to apply to pure aqueous solutlons have found some complexlng to occur with the chlorlde ion. 67,105-107 The type of complex formed between uranyl and fluoride Ions also Is subject to some question.
Ahrland and co-workers
102,104
have determined equilibrium constants for the formation of complexes U02F+, U02F2, U02F3-, and U02F42- and found no evidence for the dlmerlzatlon of U02F2 for uranyl ion concentrations less than O.lM.
Day and Powers,~
however, found no evidence for the
formation of complexes beyond U02F+; and John80n, Kraus and Young
have reported the dlmerizatlon of U02F2 in solutions
104 not very different from those investigated by Ahrland, et al.— Numerous organic complexes have been reported.~
Much of
the quantitative data Is summarized In Table VII. There is often disagreement between different Investigators concerning the nature of the completing llgand.
Uranyl-oxalate
complexes serve as an example.
The oxalate Ion, C2042-, has been 146,4g proposed by some Investigators as the complexlng ligand; 147,116 ; and Held& hae the bloxalate Ion, HC204-, by others (T4utcontinuesonpage 30.) 23
agent Hethad diat
C*02
L~# lk-m - &.gnnl.a
f2an@. Eto~tion mith &
Table V. Complew
T 25
Nedium
x
of ~L
@
O.l(clo,-) Bia2
of equilibriumOanntmyt,
y
aaetylacetone: HL
8.6, ~
8.4, y
6.b
Neferance
14b, 111
K4 6.1 “.
.
8.82
~
9.02, ~
8.25, ~
6.52
K4 5.%, P2 17.=7s P3 23.79
l!b, of.112,
113
Pa 29.?? 8P cEH502F3s thEnOyltri.nuoroauatonecm
25
0.1
25
(R.#4) (?) H3L- 2.i7 rW~L2+
~
HUL
C10%88N2 ethylemdi~tetraoetlcaaldI ’01
W
114
7.2
2.21 ~
115
25.6 #
H4L+ 2H+11.91
H&a-6.16 HL3-10.26
%er
BJerm!n, 9chw8rzenkoh, findSll16n, rwferenoe2U,
lha data, with the e%oeptlonof -Perenoe 111, hde been canpi16dby J. Mcdlor. Column one llntn the mplrioal formla, the m of the llgamd, d n rozwula or the ~ HPL whlCh defines the entiw L in temn or WMoh the equilibriumComtanta am emrenud. me liga.nfmare plmed In otier or’their empiriaalformula fboaordlng ta BellnteinlB 6yatem. col~ rlve llnta the IS mum o (-logl#) or the sold-baueewillb~ inVOIVIW the l~a and refer to the dlanooiatlon: @] [~-lL(wl-p)’1 (b-p)(=1-P)- ~+ ; ~ . + EP-lL %’ [%L(b-p)-1
.
me notnt Ion~omplahedl%llowing Table III.
2+ I. Inorganic! Coqlex P mnmtia. with U02 T,I@# MedlUM T kg or equllibriw O-amtant,remrka
Table VI, Complting agent Metlwd Cye.norerrate (II), Fe(CN):EO1
25
=
l?liooyanate,
HP
20
l(Na~O~)
2CNcart-mate,
BP mP
25
co;-
65 66 67
❑oldd
ev U@-
69
o WIT
Sol mp 25?
o
M ~P ml
-2
K[u02(02)~O(m) + C02(d# u02m3(d 63 + +014 Km2~ K (H+) 1.42, ~o~ (H+) 1.8163 63 @2 14.:, B3le.3 70 ~ ‘3.5, ~ (~2)2(oH)3L70 KJIid@#-1-2.8 b -2.0
am-r
0 cam
Ka2:o&:)
: ‘%%(m)
~o<m+)
I 002(C03):- + ym;
ml
25
BP
Nit~te, No;
+0
II -13.15 {00.76, ~ -0.o2, X30.4-4 ~ 0.93
ml mp? 25?
25
Refernrwe
+ ~w;
#
WJC03):#
+ co2(g) + ~20
U02(C03);-+ C02(E) +’B.#J
l(mqcl)
!9322.77
o.4(tmo3)
4-+ E202* U02( C03) 200H3-72 ‘E[m2(co3)3 + Em~]2.o
OP
-10
‘K 2.2
BP
-
K[uo2(uoq)2mJ’-+ E+ +
‘n
U02(C03)2OOH3-I1O.6
BP
25
5.3S(N8C104),2H+
~P
25
7(NEC1O,), 2E+
~
4.57
Mlid
w
uo&
h
Rm#o)
20
1(N8c104) ~
4.3
76
2(NW104)
-0.52(10”),-0.62(25”),-0.77(40”)
77
x-ray qh
diut, 1O-M
~
q
-o.&
74 74 75
73
Table VI. - Continued Completingagent Uethod T 7
w
Z?-a
8P
@
of equilibrium
Var
M
eV CPX: 15CM%ld
o-
‘v ‘02L3
cotitant,
Me2w
~
25
EtOH
~(?)3.15, K3(?)1.39h
00IM
25
fi2co
%(9)3.%,
re?mtin
Hderenw
L
~WBB
mti
BP
Fhoaphnte,PC?-
medium
9
78 79 80 80 81
3.6 ~ Me2co EtOH
~(?)2.46 in M02W
SP
25
mclo~
KIUCfl + ~L #
Uo.#I+xLx++ (2-X)E+II.*
sol
25
lHclo~
KIuo~ + ~L #
uo2~wLx+
e2,83
+ (2-x)H+11.57
x-10r2
or.
KIUO~ + 2H3L #
U02(H#)2 + 2H+11.1.9
K[uoy + 3E3L #
U02(k#)&L
K
aol ex
x+ U02~+ 2+x- ~;~f”~
H3L~ uc2(~L)21-117
I$L
V,,
KB[U02~(B) +
E3L
V=
Km[U02ET(s)+ 2~L #
0C2(H#.#qL]-0.55
3oO~+ ~M-6J5
~L dil
EB[(U02)3~(S)+ 6H+ #
H3L dll
KB[(u02)3L2(0)+ H3L + 3K+ e
~L dll
Ka[(U02)#2(B) + 4~L #
dll solid:
anl
+ 2E+J2.3&
[uo#L(a) + Z-I+ - Uo=
+ KBIuo B2 EL(a) + fl ~ X-1OF2
~L
25
V=
20
0
nom
83
lU02&]-2.40
3U02(H.#)21-2. e9
K~[(u02)3L2(n)+ ~L # 3U02(’H#~JO.53 To2m(0)” - uo.#Po4 (I-L-#) 4(n)
eVU02E2L+, UOfiL=,~2(~)2 H#- :~ 3.oO, K2 2.43, ~L :~<1.m, 923.8~:”;23 %[uo2(H#yJ4.53J -2.27, :114E
84,85 ‘6
q[uo2(H#)71-1. s2, -1.lB (E+ : X13 2.12)
Sol 19-2-3Wr
ICm(UO~~
L3-)-26.36
87
K.(UO~WL3- )-23.11
=+m ICB (U02
2-)-~ o,67, (H+:~ %3 ,.96
BP 25 9P 25 dlmt25 am Ox
20
12.44, %2
6.%1,
m’ U02H#+, UO&L2+, U02(~L) z, U02H~+ Vnr B(uoflH~l~Lli .1* 1.07( N8C104) 1.O7(%C1O4) EI{UC~2(~L)21113@ B[uog%:2(93n.ol~ 2++ IH3L ~ UC~(i-jH#-; jlL#2+j-i 0 Oom KIJ[UC2 + (i-j)H+J : ~. ~1
2.4J w
O.#, %1
3-9, ~.
< 1.8, Km
111, ql
Ee
E9, W E9,9C 91
1.3%
2.%,
%2 4.8, K33 5.3 y- :y 3.0,e25.5,P37.4 ~L :K1<1.8,P23.9,S35.3(mm an
%1’ %? %3) (H+:%3 2,10) SP
BP
25 1(0104-) ‘u : Klo 0.7’, Kll 7) 25 0 Oorr(
O.B, ~.
(H+ : %3
I.@)
Kij : ho
1.1, Kll 1.2, ~
(H+ : %3
2.10)
o.!, %1
1.4
Be,or. gl
1.3, ~1
2.2
88,0f. 91
~ owe equilibriumrenotion,differentnotation ~ name eqtilfbrlumraaotion,differentnotation ~ m ewilibriur$reaotlon,differentnotation
25
Table VI. - cont~ C!mple!xing agent Polyphomphats ,
T
Log of equilibriummnntant, mrim
PN
25
n-
001 21
w
K#JO~
Method
5 :~
!+e~.arenoe
3.o, orB2 6.o, or P3 9.5
92
[Pnowl 1(n-z)-
Anen8te, AaO:-
NL2-)-10.50,lfm(UO~l%3-)-18 .E2
93
Km(UO~M+L3)-21.87 Km(UO~%3-)-22. m, K~(UO:%Iq+L3)-23.77 .Sulflte, 90~-
25
Ml
2ulfate, %-
(H+:~ 11.53, %2 6.77, K132.25) U02<-,atml-# Opx K -B.59
94 95
ev
UP
BP qh
no p2 7.10
● %
25 25
2.65(Namo4), m+ 3.5(?), 2H+
~
1.E3[~(til.125J
m
1(NBC1OJ
~
1.70, ~
74
0.70
0.84, ~
74,or.61 0.86
%
p(UOV2 ‘Ao-) 3.78
25 allot 10 Unt 25
l(NnCIO~) 0 Corr 2(N-C104) 2(NP.CI01)
uBt .$c 81-,1 ex
m
ani x
25
bar
~P
25
-0
4.60 y 1.75, ~ O.w ~ 3.237 ~ 1.80, K20.96[~(Htl.011 ~ 1.88, ~ 0.97[~(H%.CW A% = 2.3,A% --0.9,A% -16,A92-2 FL-l.%, ~ 0193[~(H%.171 m U@-, U205$ e“ uo.#J I@”, U&-, U2051$ ~ 2.96, ~ ‘1
ani ex
25
EclVar
“y 1.10
@(uo:~-Ao-) m
BP 00ti
●
SP OP m COIIA dint
~Ot c%
2(N80104)
y
4.32
q
5.5, P~ -6
-o m
uo#+2 m
‘K42L?U02F2#
25
o aorr
2(NnC104) c(N8C104 )
0-30 U’J2F2 -
● %
101 (~2F2)21001a
1.74(100),1.42(25”),1.32(40”)
-5.14, A’%-,12 A*%l‘~ i.42(c-2), 1,43( c=1)J 1.W(Go.5), 1.57( ~.25),1.71( c=o.05) tK42 0.48(00),o.a5(30”)
m
m
l(tw)clo~
qh
m
1(NRC104)
1$-0.10
BP
20
l(wlo4)
y
-0.30?
0 00rr
~
0.32
~
-0.24(10”),-0.06(25”),0.06(40”)
~
4.54, $3.34,
[q(H+)2.931, m Chloride,Cl-
PO1 Up @ dlat
25
10-40 2(N8C104)
25 ~1 ux 25 25 25 OP ? W
2(N8C104 ) HC1vnr 0 mm -o &
BP
Perchlomte, CIO~❑P Emnd.de, Bra
67
35
y
10-40 2(Ilac104)
25 25
93
100,Oz 101
4.59, ~ 3.34, ~ 2.56, K41.36 [q(2+J2.941 $-4.4,.. other OPX
)
n w
100
w
1(WWJ4
96 97 77 77
~
~
2.57, K4 1.34
WV Wlyn Upx for < O.in-uoy
102 103 77 77 77 36 102, 104 of.104 76
76 105 +7
w 3.8,AS$-12
77
evcmioFcx ti>o.5M-HCl
i06
~ -0.1. K2-0.82, ~ -1.70 ~ 0.21 no OV OPX : 15J-fold OXMBB L-
N’32CU
w
25
2-6CIo~
noev
20
1(Nncloq)
~
26
UO&+, U02~, U02L~ Cpx
-0.30
106,M. 107
67 50 108 1C9 76
l’nblem.
- Cantl.m-sd
C&nplexlngagent Metlmg T
Iodate, 103-
Medium
25 25 60
Sv sol
Bol
Log of eqtd.llbrlum oonntit, I.EUUZ-ICB R9remnae
+0 ~ -0.20 P33.67 o.2(m4cl) K -’7.01,B2 2.73, no 0.2( NH4C1) Kmo-6.65, P22.74, )93 3.44
67 110 110
E After Bjerrum, Sohwarsenbach,and Sill&n, raferame 20. Data mhlah iipm.wwl ~ by the above authom.
the literatw
-or
l%e tiaticm IB explalmedfollo~
Method
Ft
oat~
ompll@ ~
with Uoj” Imm
T
Medium
PK of HDL
25
o Oom
I-$L1.27
25
J. aI~~.
Table III,
Table VII. Complex ~matlon Carnplexlng agmnt
to the xdd41e of 1957 han bean oaupiledmostly
?mbnequentdata hBn baen
0.16HC104
m-
4.29
I&
1.28
~-
3.75
- OrKanio L@8.II@
LOB of ewlllbrium oonatant, relna*0 ~L :K12.57 ~ 5,E2, K2 ti.74,
Reference
49
HL-: ~
3,4o, K2 2.s6
116
Oat= 25 Oak- 25 ~c20~ 25
lHCIO&
R.-#1.28
m-: ~
2.83, K2 ‘1.85
116
‘mclo@
H+
I-L-:~
2.89, K2 ‘1.85
116
0.069
‘K[(U02)2L2-+ 2L2- # 2 (U02)A-14.42
A22c204 25
0.022
‘K 4.63, %[(U02)#~-
1.2.9
117 + L2- @
2(U02L2)=’-11.32 It[2(UO@2-
4c20& 25 aol
O.ooe
20
HL-4.19
+ L2- #
117 (U02)~6-13.~
$’2-0.42
117
~
118
6.77, K2 5.23, P, 12
KIuo~ + H&
- UO@
+ 21#J1.60
&- +~.UljL2z p + 4H+11.6S K[U02 ❑01
20
Eclo
K6[UOyL2-(~0)31 -8.66
llE
01
20
KN03, > 1.5H+
Ka [uo~ L2-(~o)31-B.52
llE
25
lHclo~
6.56%~fi~ly, 6.~02Julytl116, oz tally, P210.74 11s 116, cf. 1 18 y 6,52 119 ~ 6.oo, ~ 5.02, 4.~ (Pl-3r~rred VEiLUe ) 1 120 ~ 2.1
❑
oat ex
>1.M+
4’
oat .3x 25
2HC101
001
*O
25
Sp gl
0.92
m
K1
0.05
K[2uo# + ~02 #
up gl
0.312
C2H402
mf
lMaC104
FC[ 2uo#:- + %!02 ~ (“o2)2(@L$- + 2E+J-3.66 ~ 2.30, K2 1.93, K3 1.%
aoeti’oacid}HL
pa
a
ap 20
4.59
~
NaL-i-Z buffer
2.63, ~
(U02L)2(W)2- + 2H+1-1.62
e.03, ~
lm 1.20 121 64
1.60
25
0.16(N8C1)
~
2.32, B3 6.?&
122
ion ex RT
0.5(NaN03)
~
1.=, !s35.89
123
C2Hh03
gl
20
lNaC104
?j 2,42, ~
@yOOliO .aold :~
cat eX
25
PN
25
eti
20
3.56 o,16(Nacl) 0.16-0.19 lNaC104 2.66
oat ex
c2H302c]
~
1.54, ~
2,78, ~
1.30
1$2.75, ~
1.52
~
1.44, 1$0..95, q
124
1.2U
116
-
116 =5
0.51
,..
27 .
Table vII. - Oanthued COmphx.lngagent
Method
chloroacetlcaaid:HL BP CHON 252 glyoine:EL C2FI@N2
T
Medium m ofFIPL
LOE or equlllbrim oormtant,
11WC104 2.66 20 NaCl) H++ 2.32 25 0.45( pHl,W ~+ 8.06 25 0.15-0.25
Refaranae 125 122
126
glyalne amide:L
HT RT
C3H603 laotlo acia:HL
25
127 12e
0.45(KaCl) E$L+ 2,21
116
PH 2.05
m
127
m!
m
C4H606
127
tartaria aald:E# ~P>PR
HT
gl
30 10 25
evuoy/t8rtAeam h ratio l/’l an 1z% &heracid solution;3A and 3/2 @-z
C5%C2 acetylacetane:~
G tint
+0 +0
0.95 9.10
~
7.74, ~
6.43
~
7.9h, ~
6.53
129 129
Kl 6.8, K2 6.3
O.l(CIOi) E.82
K[U$%
51, 111
L- + EL #
U02L(FZ)+JEL7
KIuo~+ 2L- + I-Z● UO&@)!14.8
C6F%06 aacorbio
❑P,PE
25
EWE
=-21
O.l(lwclou) E-#4.07
HL : ~
5-
2.43
80
1~o
‘ 52”@
PH 2-3
acid: (H2L )
*P C6%C7 cltrlc acid :H4L pal
FrT
WV uo:/citmte
(NEacl )
and 2/1 @
Opx h
Patio l/1
2-6
1?1.
30
.svUO~/0itr8te cm
in ratio In
❑P,PH
RT
ev UO~/aitrate opx in mtlo y~
❑PSM
7var
RL3-: q
prement aa dlmer PH 4.6
and3/2PHB
ev U&/Oitmte
25
0.15(7)
H4L 2.94 ~L-
C6H902N3
PH
histidine:HT SP ‘YW2 mlicylaldehyda:FL
BP WW3 eallcyllc a61d:H# dint
HL3-: q
128
3.165@
OV UO#L- #
aond
e.5
1?2
4-7
UO&2- + H+
133 pH 4.6
apx in ratio 2fi pE 7-9 134
4.34
lL#25.62 0.15-0.25E#+ 6.17% 7.17 126 m g.m ? 50$2toH ~ 1.81UWl .cetate, 135 U.aetlo aaldprnnant, PH3 w B22.63urwnyl nltnte, PH5 136 y 13.4 o.l(lmclo~) H.#2.02 2L-: ~ 2.2 138 25 m,-13 KIuo~ + I-Z,+ OR- # U02(HL)(OH)112.1
25
‘an
Table VII.- ContlnueQ Completingagext
Methd
%%
gl
30 5@ d~om
9.40
EP
25 =0.015
~L- 2.s6 NL2-: q 3,B9
140
0.09
141
kojic
T
Nedium
PK Of HPL
Log of equilibriumcmn4tant, relmirkn
Fmfemca
K2 7.4 ~ 10.1,
139
acid :KL
C73606S 5-OUlf o=lIwIIo acid :H3L
C#T02N
BP
~ 6.40, ~ 4.9’7
w.licylmlde :~ c7H1102N3 hllgd+e methyl C8H60N2 8 -Ivdrmycmolme
m
25 0.15-0.25~L2+5.38 ~ 5,76 ~+ 7.33
126
gl
20 5@ dloxanH.#+1.77 K1B.ES,~ 7.16
142
:Hz
CBH60N2
20
a
5-hydroxyqtioxe.ltie :FIL CBg60N2
gl
20
8-hydmvqutizoltie:~
C9YN inollce :HL
T“
(oxlne
HL e.e4
5@d10m
E&+<l
0.3 NBC104
I-L9.29
~ 8.99, ~ 7.7o
142
9.59
25 0.1(NaC104) 3.@9
K [UO~
gl
20
~
aimt
0.3N8ClobKL10,80 25 0.1
63 23.76
20
K1 9.W, ~
5C5 aioxan N.#+ 4.48
3@ dioxan H.++ 2.59
:HL 0.3 NaC104 ~ 9.00 pH,Hp 25 0.1 2303 H2L3.84 WY4~9 0-hydroxyqtinollna -5-sulphon~c ao~d: HL-B.35 %
8-hydmxy-4-methy
+ L- + OH- ~
142 143
7.30
142
lOtiOltie
~
8.52, K2 7.16
144
K[U02(OH)L:-+ H+ @
K[2U02(OH)~- ~
H dlom H#+ 5.01 0.3N8C104HL11.01 gl m 5C$~loxanH,#+4.71 cloNgo~ 8-tvdmW-5-netQlqulnol ine:~ 0,3N8c104 HL 13..11 dio~ H.#+4,76 20 5c5i a C1OH9ON 0.3mclo~m 10.71 8-h@row-6~ethylqutiollrm:~ H2L+4.26 gl 20 5@ dloknn C1OH9ON HI11.31 B-hydrow-?+nethylquinolhetHL 0.3NaCIO~ clo~oo:$ gl m 50$tioxan H2L+ 3,15 gl 20 %oH90~ E1-hydroQ-2-methy lquinollne:FU
8-hydroxy-2:k-dlmet?@@nazollne:~ gl
20
1:2:3:4-tetrahydro-9hydrowncridine:iiL a C15H12CN2 8-hydmn-4-methyl -2pherrylqulnauoltie :!tL
5G$ dioxan H&+
5.49
~
6.69
2uo.&ll.7
(U02(OH)L2)~-]1.7
~ -9.4, ~ -2
142
~ 11.25, 9.52
142
~ 10.B9, ~ 9.26
142
q 11.2E, K29.78
142
y 0-77, ~ 7.33
142
q 10.10, ~ 8.2@
142
0.3 NaC104 KL 11.39 20
B.53, ~ 7.85
142
0.3 NaC104 HL 11.33
(NH4)#-(?) :q
~ Af tar Bjerrwm,
and Sill’en, refemnoa
Schwarmnbaoh,
K1
50% dlaxnn ~L+ < 1
V=
appeared
UO&-~
HL 10.14
25 BP c22H2309N3 amnonium aurintricuwbotilmte (aluminonreagent),: (Nl~)N#
Data wh~ch
U02(L)(OH)]11.9 132
11.25, K2 9.64
K[(U02(OH)L2)~-+ &
c13H130N
142
~ 8.40.$7.51
50% dioxin H2L+ 3.30 0.3 NaC104 ~
dint %%03 methnxybenzoloacid:HL
E-hydro
0.3 NaC104
in ths’ litiratura
above 8uthom.~bmquentflnta bm ~ ‘1’lm notation In exgla~d following
b.77
20.
1956~a han oompiled mntlybyt~ compllti byJ,GindloP.
prior
Tables
to
111 and V.
.29
145
stat’e~that a complex Is formed with undissoclated oxalic acid, 118 conclude H2C2040 In more recent work, Moakvln and Zakharova— that comPlexes maY be formed wfth both C2042- and HC204- ions and that the amount of each formed will depend upon its stability and the conditions of the experiment. The compoaitlon of a complex Is sometimes decided upon by comparison with complexes having similar ligands. li8k-Bernatrom,~ metho~benzolo
In her work with salloylic acid, H2A, and acid, HB, was able to show that complexes of the
type U02(~A)(H+)-1, fomed
For example,
U02(H2A)(H+)-2, and U02(~)(H+)-2
In the aqueoufl phase.
that H+ was eltinated
were
(The negative subscripts indicate
In the formation of the complex.)
experimental data for metho~benzolc
The
acid waa approximated by
assum!lng only the complex U02(B)(OH).
For sallcylic acid, the
complexes U02(HA)+ corresponding to U02(H2A)(H+)-1 and U02(HA)(OH) or U02A corresponding to U02(H2A)(H+)-2 were postulated. It was not possible to dlstlngulsh between the latter two. However, from
the strnllarl~ of the distribution curves f@nd
for the
two acids, it waa suggested that the ~allcylate complexee are formed by HA- llgands: A vaat amount of work other than that listed In Table VII has been done on the preparation and Identlficatlon of organic uranyl complexes.
Some of the completing agents studied recently
Include dlhydroxy-malelc acid,—148 trlose-reductonu (enoltartronaldehyde), reductlc acid= one-l), complexone~
(cyclopentene-2-dlol-2,3-
(Imlnodiacetic acldand
xanthates and dithiocarbamates,~ protoporphyrln,~ 16 acid,~ mlrlcltrine,~ diallcylphosphorlc acids, ~
its derivatives), o-cresotic and
pyrazolone derivatlves.—160 3.
Non-aqueous solutlons of uranium. Solubillty studies.
A number of uranium salts are
soluble In organic solvents. example.
Uranyl nitrate is the’notable
As the hexahydrate, this salt is soluble in.a.. 30
variety of ethere, eatera, ketone~, alcohola, aldehydea, and wb8tituted
hydrocarbon. _
zatlona have been mad~
The following generall-
concerning It, solution In o~ganlc
solventO: (1) In a given homologous BerleB, the aolublllty decreaOea as the molecular vrelght of the solvent Increases. w
(2) Solutions occurwl.th:~ Ethers:
alfphatic ethylene glycol dlethylene glycol ~aturated cyclic
Acetals Ketones:
aliphatlc aromatic allcycllc mixed allphatlc-aromatic
Alcohols:
aliphatlc alicycllc
Various esters Nitrogen-containing
solvents: nltrlles aromatic bases
(3) solutions do not occur with: Hydrocarbon= Ethers:= Sulfur-contalnhg Gweckauf’66 —
aromatic unsaturated cyclic
aolvents.—165
has made the phenomenological
observation
that a plot of the solublllty of uranyl nitrate against the oxygen-to-carbon ratio In the solvent molecule results In a single curve for alcohols and ethers; b~t in a double curve for ketones; one for symmetric and one for asymmetric ketones. Ionlzatlon. byMcKay
The quantity (A~\constant)* has been used
and co-worker-to
estimate the degree of
lonlzatlon of uranyl salts In organic solvents.
By this
criterion, uranyl nitrate In concentrations of 0.01 - 1~ Is * A = molar conductivity. T = viscosity. used for 1:1 - electrolytes; 120 for 1:2 31
The constant 60 IS electrolytes.
subrstantlally unlonlzed in water-saturated * ketones, alcoholB and tributyl phosphate.
solutions of ethers, Only In saturated
dlethyl cell”osolve and In isobutyl alcohol Is Ionlzatlon In excess of 10%.
The large amount of water which dlssolvea In
the latter solvent may account for this. In tributyl phosphate, the dissociation of ura~l
nitrate
Increases as Its concentration In the organic phase Is decreased.
lit10-5~the
salt Is approximately 40 per cent
dlsEoclated,—169 i.e., Aq/120 = O.k Uranyl perchlorate at this concentration Is almost completely Ionized. @
Ion
association occurs at higher concentrations, but significantly less than for uranyl nitrate.
At approximately O.01~, the
association of uranyl perchlorate is maximum (ArI/120has a minimum value of ‘0.1) in the concentration range 10 -5 to lg. The ionization of this salt may well be associated with the amount of water contained within the tributyl phosphate since 169 the electrical conductivity is decreaaed by dehydration.— Jezowska - Trzebiatowska and co-workera~
have measured
the molar conductivity of uranyl nitrate in organic solvents that contain only water from the hexahydrated uranyl salt?* The conductivity was found to be low and to decrease with a decrease of the dielectric constant of the solvent. Conductivity measurements of UC14 in methyl alcohol indicated the salt to be somewhat dissociated.=
The
dissociation was found to increase on addition of tributyl phosphate. Kaplan, Hlldebrandt, and Ade@@
have classified into
* Solvents tested other than tributyl phosphate: diethyl ether, diethyl cellosolve, dlbutyl carbitol, methylisobutyl “ketone, isobutyl alcohol, and iso~l
alcohol.
**Solvents tested: methyl alcohol, ethyl alcohol, acetone, ethyl-methyl ketone, methyl isobutyl ketone, acetylacetone, stannous chloride in acetone.
32
typeg the abaorptlon ~pectra of uranyl nitrate In a number of’ * Differences between types solvents and solvent mixtures. w’ere attributed to a aerlea of hydrated and solvated nitrate 2+ and U02(N03)3-. complexeb, iJ02 ‘ ‘02N03 + ‘ U02(N03)2,
The
relatlve concentratiorm of the complexes depend upon the nature of the solvent, Lta water content, and the concentration of added nitrates.
It IS Intereatlng to note that the absorp-
tion Bpectrum of uranyl nitrate in trlbutyl phosphate (0.016 1,6
~)
Is
characteristic of the complex U02(N03)2 and indicates
168 little ionization.—
A stillar spectrum Is given by uranyl
nitrate In methyl isobutyl ketone (0.02 ~).~ ate In methyl Isobutyl ketone (0.02 @, spect~m
Uranyl perchlor-
however, exhlblts a
characteristic of the uranyl iOn, U &p
.
These
results appear to be In general agreement with those obtained through conductivity-vlscoslty measurements.
167-169
The trlnltratouranyl complex U02(N03)3- has been studied by a number of workers~8$7g’ ‘7’-’73 It is formed by the addition of a second soluble nitrate to a solutlon of uranyl nitrate In a non-aqueous solvent such as anhydrous nitric acld,~
dinitrogen tetroxlde, ~acetone,~
isobutyl ketone, ~ workers
dfbutyl ether,~
etc.
methyl
Kaplan and co-
also report that the complex 1s formed In 16 ~
nitric acid, but that ltS formation Is far from complete. The negat~ve character of the complex has been demonstrated by electrolytic transference expertients.—78
Its composition
has been deduced by the Isolatlon of solid compounds from eolutlons of the type described above 79,171,172 and by the similarity of the absorption spectrum of such solutions with that of crystalline cesiumuranyl
nitrate, CsU02(N03)3U
“Spectra classified: uranyl.nitrate in water, acetone-water, dioxane-water, n-propanol-wat&r, ethanol, chloroform + 0.7~ ethanol, pyridlne, acetic acid, ethylacetate, tetraethylene glycol dlbutyl ether, nitroethame, methyl isobutyl ketone, cyclohexanone; uranyl perchlorate In methyl Isobutyl ketone.
33
The stabillty of the complex depende upon the nature of the RBBOCtEited cation as well aO the nature of the solvent and the prepence of water In the solvent.
The general order of
the solvento with reBpect to etabllity of the trlnitrate complex is: ketone > ether > alcohol > water<= The formation of chlorouranyl complexes In non-aqueous solvents has been reported by Vdovenko, Llpovskil, and ~ikitln~ The complexes U02C1+, U02C12, U02C13- were formed by the addition of pyrldlne hydroohlorlde o“rhydroxylamine hydrochloride to a solution of ur~l or uranyl chloride in acetone.
perchlorate
The stability of the trl-
chlorouranyl complex was found to be dependent upon the amount of water present in the solvent.
A compound was
separated and identified as (C5H5~)2U02C14. Hydration.
In partition studies of uranyl nitrate
between aqueous solution and organic eolvent (alcohols, esters, ethers and ketones) it is generally found that the water content of the organic phase increaaea with uranyl nitrate concentration.-’
Foralcohola,
the relation
between the water content Mw and uranyl nitrate concentration ** For eatera, ethera, Mu appeara to be a complex function. and ketonea the relation la linear except possibly at high valuea of ~.
This relation may be expressed
The quantities are expressed in terms of molalltiea of the dry solvent.
M; la the volubility of water in the pure
solvent; h Is a constant.
The saope of the line, h, repre-
* The water content of alcohola may decmeaae initially aa the trate concentration la increased from O to 0.1-O.2 :E::& *’*Ka~zln and Sulliva@ report a linear relation b M and ~ for Iaobutyl alcohol. McKay and Mathieaon&~int btit that if the data of Katzln and %llivan at low ~ are given significance, then a more complicated relatlonahip between the two quantities exiatam
34
For many of the “llnear
sents the degree of hydratfon. 16 9olvents h is very nearly 4.0.~ preted by Katzir@
16
Thin hae been inter-
to mean that the species U02(H20)4(N03)2
McKay,—175 however, considers this to be a
is extracted.
nean hydration number; that a series of hydrates are pres~nt ranging from the di- to the hexahydrate; that these hydrates me
in equilibria
stability.
with each
other and are of comparable
The latter view is supported by isopiestic
measurements.~ Infrared measurements on ethereal and ketonlc soluti~s* of uranyl nitrate, indicate two molecules of water to be strongly bound to the uranyl nitrate and the remaining water molecules to be more weakly bound.~ The extract~on of uranyl nitrate from an aqueous ayatem into tributyl phosphate
(TBP) causes the displacement of
168 The displacement is roughly water from the organic phaee.— 168 linear with h being -2.— This iB in agreement with the formulae TBP”H20 and U02(N03)2”2TBP.~
Uranyl perchlorate,
however, apparently does carry some water into tributyl phosphate.~
Whether this water iB associated with free
Uranyl ions or unionized U02(C104)2 is undetermined. Solvation. in particular 163,180-182
The isolation of solvated uranium salts, 6 uranyl nitrate,is reported in the literature.—’
In phaae studies of ternary systems: uranyl
nitrate, water, organic solvent, Katzin and Sullivhave concluded that uranyl, nitrate in aqueous solution is largely hexasolvated, subject to the activity.
As organic
molecules are dissolved, 2,3,4 and perhaps 6 water molecules may be displaced, depending upon the electron-donor capabilities of the organic molecules.
The total solvation is a function
of the activity levels of the water and organic molecules.
* Solvents studied: diethyl ether, acetone, methylethyl “ketone.
35
If a parâ&#x20AC;&#x2122;clcular configuration la stable enough, It may aurvlve as a cryattiltne aolld.
The particular etabillty of the final
two w&ter molecules la tn agreement with the reeulta of F&akin and co-worker-obtained
through Infrsred ab80rptlon
The ablllty of ~olventa to displace water. is ~ ~IS general In the order: alaohols > ethera > ketonee.
memurementa.
order of aolvate 8tablllty Is confirmed by beak of aolrition measurement. ~
It la in agreemnt
aleo with the order of
baae (electron-donor) BtrengthEi of the eolventB determined by other meama.a
methyl iOobu~l
ketone 10 ano~loua
In
that It behavea stronger toward ursnyl nitrate than lt~ batme strength would indicate. _ to heat meaauremnts,
Tributyl phosphate, according
oompetes wtth water almost as well aB
dlethyl ether and Iaobutyl aloohol.~ The order of solvents with respeot to 8olvate stability la op~site
to that with re6peot to the stablllty of the
trlnltratouranyl
complex.
This eug.gests a competition be-
tween solvent umlecule and nitrate Ion for coordlnatlon ~ with the uranyl ion. Feder, ROBS and Voge*
have studied the stability of
molecular addition competands with uranyl nitrate. pounds were prepared by shaking uranyl
The com-
nttmate dehydrate with
varloua addenda In an inert solvent: benzene and/or 1$2dlchloroethane.
1:1 molecular addition compounds were found
with uranyl nitrate and ethyl alcohol, n-dodeoyl alcohols tetrahydrofuran, propylene oxide , meal~l phosphate, and N,N-dlbutylacetamide. observed with uranyl nitrate
oxide, tributyl
1:2 compounds were
and acetone, mthyl
isobutyl
ketone, cyclohexanone, ethyl acetate, 2,4-di.methyltetrehydrothlopene 1,1-dloxlde, p-chloroethylacetate,
ethyl chloroacetate,
ethyl cyanoacetate, dlethyl ether, al!kyl alcohol, ethylene chlorohydrln, and acetonltrll~.
FormatIon conatanta were
determined frmm changea In the aolublllty of ureJ@ 36
nitrate.
It was shown that the ~tabillty of the addltlon molecules, for those addenda having s~llar
functional groups, was in
agreement with the base strength of the addend; I.e., the more stable the molecule, the greater the baae strength df the addend. The average number of Bolvate molecule~ n associated with uranyl titrate In Its partition between water and varldus organic solvents * haa been Etudfed by McKaym and c!o-worker6. The value of n was found to vary with the uranyl nitrate concentration of the organic phase.
For
most of the solvents studied, n varied between 1 and 4. For cyclohexane, considerably larger values were found for low uranyl nitrate concentrations. A saturated Solution of uranyl nitrate hexahydrate in t~lbutyl phosphate corresponds cloBely to the unhydrated di601vated compound U02(N03)2”2TBP.W
Evidence for
the existence of the single species 1s:w (1) The solublllty is not appreciably temperature dependent over the range O-50”C. (2) On freezing and rewarming a saturated solution, a Bharp
melt.ing-po~nt
of
-6.0
f
0.5°C Is observed.
(3) The mole ratio of uranyl nitrate to TBP approaches the value 1:2 asymptotloally under a variety “of conditions. (4) The effect of Inert dlluents for the TBP onuranyl nitrate partition coefflclente supports a 1:2 formula, I.e., the partltlon coefficient of uranyl nitrate varies as the square of the TBP concentration. The experimental condition under which Feder, Rosa 184 reported the formation of U,02(N0 ) ‘TBP were and Vogel— 32 168 considerably different from thoBe of Healy and McKay.— * Organic solvents studled: dlethyl ether, dllsopropyl ether, dlethyl cellosolve, dlbutyl cellosolve, dlbutyl carbltol, penta-ether, Isoamylacetate, methyl Isobutyl ketone, cyclohexanone.
37
Jezowska -Trzeblatoviska, etal~rwpo~t
that the
absorption spectrum of uranyl nitrate In trlbutyl phosphate glvea no indication of tlie formation of a stable complex. Attempts to identify a complex apeclea In the concentration range 0.02-O.O~_ were unsucceaaful. Heaford and McKay~ of U02(C~4)2:2~p
report evidence for the formation
under certain conditions.
From a 10.3~
aqueouh perchlorlc acid solutlon, the partltlon coefficient of uranium varlea as the square of the TBP conoentratlon In benzene.
Under other Gondltlona,
Jezowaka - Trzeblatowska, et al=
other aolvates may be formed. report the formation of a
1:1 complex between UC14 and TBP In methyl alcohol. Trlbutyl phoaphlne
oxide, like trlbutyl phosphate,
forma an anhydroua dlsolvate with uranyl nltrate.—187 Healy 188 ad Kennedy— report a number of other neutral organophoaphorua solvents which fom
aolvatea with uranyl nitrate.
Mo”st, but not all, of the solvates reported are anhydroua. All of the solvents extract uranium from aqueoua aolutlon in proportion to the square of the solvent concentration (In benzene). benzene and
However, not all solutlons of the solvent in
saturated In uranyl nitrate give mole ratios of
solvent to uranium of 2:1.
For the two dlphoaphanatea and
one pyrophoaphate studled the mole ratloa were 1:1.
ml s
may be indicative of chelatlon or polymer formation.
The
mole ratio In trlphenyl phosphate was ‘22:1.
This Is
probably the result of the solvent being unable to displace 188 water from the coordination sphere of the uranyl lon.— Solvate formation between uranyl phosphorus compounds, e&mono-
salts and acid organo-
and dl-alkyl phosphoric acida
haa been the subdect of some Investlgatlon. 80,158,159, 188 1:1 complexes between uranyl nitrate and mono- and dl-butyl phosphate and mono- and dl-amyl phosphate In ethyl alcohol have been reported.~
In explanation of dlatributlon data
38
In conjunction With lt30ple8tic and vlacoslty measurements, Eaes, Zingaro and Colem~ 158 have hypotheBlzed that UPRniWII (VI) is extracted from aqueous perchlorate solutions Into n-hexane solutions of dl-(2-ethylhexyl)-phosphate,
HL, as
the species U02(ECL)2L2. As the uranium concentration of the organic phase is increased, there is strong e.vldence occurs. ~
that polymerization made by Dyrsse~ (W)
Similar conclusions have been
on the basia of the distribution of uranium
between aqueous perchlorate solution and dibutyl phos-
phate, HK, in chloroform. and
In hexone, the species U02(HK)2K2
U02K2 have been identified.=
The extraction of
uranium (VI) by dibutyl phosphate from aqueous nitrate solutions into benzene has been studied by Healy and Kennedy.â&#x20AC;&#x201D;188 In addition to the species U02(HK)2K2, the polyuranyl species (U02K2)X2HK and the nitrated species U02(N03)2
. 2HKhave
been
postulated to explain the shape of the extraction curve aa a function of nitric acid concentration. It has been postulated that the forntatfon of mixed eolvateB or solvated chelates enhances the extraction of uranium into certain solvent mixtures.
These systems are discuOsed
in a later section on solvent extraction.
IT-D
Separation of Uranium
A number of review articles have been written on the analytical chemistry of uranium. 6,34,189-200
These, together with many
texts on chemical analysis (see, for example, references 201-209), serve well as ~ides ment.
to the separation and purification of the ele-
More specialized surveys have been made by Hech~
quantitative ticro-analysis
on the
of uranium-bearing minerals, and
by Lawrowskiâ&#x20AC;&#x201D;211 on separation processes for the recovery of nuclear fuels. Two general techniques are available for the separation of uranium.
(1) Uranium is removed from solution in the presence
39
of contamlnanta by precipitation, solvent .extraotlon or some alternative method. (2) Uranium Is kept In solution and contaminants are removed.
These teâ&#x20AC;?chnlques are facilitated by the
fact that uranium is reasonably stable in two oxidation states, (IV) and (VI), and that complex formation may be effected to prevent the removal of either uranium or contaminant from solution. In the followhg precipitation,
paragraph,
the separation of uranium by
eolvent extraction, and ion exchsmge are described
in some detail.
Reference Is made also to other methodO of repara-
tion: chromatography, electrodepo~ltlon, volatilization and pyrometallurgy.
1.
Precipitation.
In classical systems of analysis, uranium
i~ a member of the thlfi group of elements. *
That 1s,
it Is not precipitated by hydrochloric acid or by hydrogen sulfide In an acidic solutiion, but It Is precipitated by smmonlum hydroxide or ammonium sulfide (see referenceO 204, 206, 208, 213).
Unfortunately, for the separation of
uranium, many other elements also are precipitated by the same reagents.
However, there exists a large number of
reagents capable of precipitating uranium over a wide range of pH.
These, combined with ~udiclous use of the two oxidation
states andjor
the ~omplexln~
ability of uranium, my
be used
to provide reasonably pure uranium deposits. Precipltants. With t~e advent of nuclear ener~
as a
source of power, numerous preclpltants have been investigated In an effort to find one specific for the separat~on and\or determination of uranium. date.
War=
None have been found to
has aunnnarlzed early work using organic rea-
*
In the system outllned by Noyes and Bray ~ uranium Is precipitated In the sixth group with smnonfum hydroxide and Is converted to the sulflde with hydrogen sulfide. In the system of West and Parks,= uranium Is precipitated in theâ&#x20AC;&#x2122; fifth (basic benzoate)group.
40
gents as preclpltants.
Sh&
and ~fley~
some of the more promising ones.
have investigated
Rodden and Warf~
have
discussed the use of many reagents, both Inorganic and organic, end have described procedures for the use of many of them.
The
latter precipltanta, I.e., those for which procedures have been given by Rodden and Warf,
~
are denoted by a dagger (t) In the
foliowing discussion. Inor~nlc
preclpltants.
The reagents are listed alpha-
betically according to anion. Araenate~.
t
Arsenic acid and ammonium, sodium and
potassium araenate preclpltite uranium aO uranyl metal arsenate. Silver, titanium, zl~.onlum, thorium and lead interfere. Separation Is made from the alkali metals, alkallne etD?thB, aluminum, Iron (H),
and rare earths, Includlng trivalent
cerium.~ ~arbonate~.6,63,201,204,206,217-224
~mtipitatlon
of
uranium with armnonium, Bodlum, or potassium carbonates Is not very satisfactory. are formed.
Highly soluble carbonate-uranyl complexes
Under proper condlths,the
ate salts M4Uo#c)3J3are fo~d.
metal uranyl tricarbon~
The solublllties of the
respective ammonium, sodium, and pota~elum ssd.ts In water are 50(15”C) ,@150(RT),+ liter.
and 71(18°C)-
graum per
The BOlub~lity of the potaeslum Bait in a 5@
tion of potassium carbonate Is 0.200 gram
BOIU-
221 per ll’cer.—
The volubility of the sodium salt Is decreased by increasing 223 temperature and by increasing sodium salt concentration.— Te%ak~
has studied the preclpltatlon of uranium by
ammonium and Sodium carbonate.
From a 0.0431Jurar@
nitrate
solut~on, precipitation wa~ observed to be maximum In the region of O.111precipitant concentration. —
Two maxima were
observed for ammonium carbonate; one for sodium carbonate. Above and below these fatrly narrow regions concentration, uranium enters into solution. 41
of precipitant
The uranium (IV) salt, Na6U(C03)5 “ 11~0
IB precipitated
from reduced carbonate 8olutions at high uranium and csrbonate 63 concentration .— Barium uranyl carbonate aalta sre reported to be very However, In the presenoe of mrbonate
Insoluble. ~
solutiong
the alkaline earth salts are unstable according to the reaction,~ MJJ02(C03)3 Tezak~has
[uo2(co3)314- +Mco3(~).
(B) +2CO:-=
found the preoipitatlon of uranium to be nearly
complete when the barium:uranium ratio is greater than 600 end the excest3 carbonate is less than four times the barium concentration. A suspension of barium carbonate may be used to precipitate uranium. 34J226
-ni~
suspension of baOia zinc owbonate
salts interfere.
A
may be similarly u8ed.=
Iron, aluminum and thorium also precipitate. Cyanides.
Alkali cyanides form a yellow precipitate 34 when added to uranyl solutions.— Ferrooyanldes. +
The addition of potassium ferrooyanide
to a uranyl salt solution cauaes the formation of a deepred precipitate or suspension, depending upon the concentration of uranium. ysis
The reaction is used much in qualitative anal-
?or the Identlflcxatlon of Ur~lUUh
However, it IB
llttle used for quantitative separation.
The separation is
poor and there are many lnterferenoe6. ~
Separation can be
228 made from beryllium In a weakly acidlo sulfate Bolutlon.— Fluorldes. + Hydrogen fluoride precipitates uranium (IV) as the tetrafluoride. difficult to filter.~
The precipitate is gelatinous and Separation Is made from metals com-
plexed by fluorlde Ions, eg., tantalum and zirconium.
Uran-
ium may be reduced to the (IV)-state with zinc in a solution 196 M slightly acidlc.—
42
The double fluorldes, eg. , NaUF5, are sparingly soluble even In the presence of strong acids.—196
Separation can be
made under these conditions from Mo, Ti, Nl, 00, Mn, Cu, Fe (II), and V (III). ~umln~ Na2AlF6.
precfpltatea as the double salt,
Iron (III) precipitates In part.
Reduction to
uranium (IV) may be done in the preBence of fluorides with Rongalite (Na2H2S204 “ 2CH20 “ 4H20) a180
iron (11).~
has been used to effect reduction. z Hydroxldea.
The addltlon of a mebal hydroxide to a
solutlon of uranyl salta reaulta in the formation metal uranate.
It has conunonly been ~mmed
of the
that the metal
diurante, M2U207, is precipitated by ammonium, sodium, or potassium hydroxide.
However, experimental evidence indl-
catea that the compo~itlon of the precipitate depends upon the condltlona which exist during precipitation and upon the mbsequent
treatment, Buch aa waahlng, which It re-
ce~ve~.~ Ammonium hydroxide+ preclpltatea uranium quantitatively atpH 4 or greater. Y
The presence of ammonium salta and
macerated filter paper facilitate precipitation.
Separation
Is made from alkali metala, alkaline eartha, and cationa fomlng
anmonla complexes.
Repeated precipltationa may be
neceaaary to give aufflcient aeparatlon.
Phoaphorua, vana-
dium, alllcon, boron, aluminum, iron and other elements of the auuuonlum hydroxfde analytical group alao =e
212 precipitated.,—
Completing agenta: carbonate, oxalate, citrate, t~trate, fluorlde, etc.3 Tnterfere. Precipitation with alkali metal hydroxldea ia slmllar to that with amonlum
Uranium may be precipitated
hydroxide.
In the presence of carbonate with aodlum Or potaaalwn hydroxide of aufficlent concentration.
Carbonate Ion
be removed by heating.
43
interference may
Pale green gelatinous U02 o H20 16 precipitated from uranium
19 (IV) solutions by amnonlum and alkali metal hydroxldes.—
Iodatea. +
Uranium (IV) Is precipitated from an acid
34 aolutlon by pota8aium lodate.—
Separation can be made from
copper, molybdenum, and reduced vanadlum.—238
Alumlnum In
amounts up to fifty times that of uranium does not Interfere. Larger amounts of alumlnum and dlvalent Iron In any concentration cause Incomplete precipitation.
Titanium, zlrconlum,
cerlum (IV), and thorium precipitate with Iodate.~ Mercuric oxide.
Uranium is precipitated when a
suspension of mercuric oxide is boiled in an aqueous solution containing emmon.lum chlorlde.~ 4
Separation is made from
alkali metals afidalkallne ea~ths. Peroxides. T peroxide, U04
●
Hydroxy acida Interfere.
Hydrogen peroxide precipitates uranium
XH20, from sllghtly acldlc solutions.
reaction occurs In the pH range 0.5-3.5. IS 2.0-2.5.
The
The optimum range
Hydrogen Ions released with the formation of
uranlvm peroxide are neutralized with ammonia or ammonium acetate.
Complebe preclpltiatlon requires an excess of
hydrogen perofide.
Quantltatilve separation may be effected
by freezing the aolutlon, allowing It to &tend, and filtering at 2°C.
The separation from most elements Is good since It
Is done from an acidic solution.=
pluton~u,
hafnlum, zlrconlum, and vanadium aleo precipitate.
thofi~, Iron
interferes by catalytically decomposing hydrogen peroxide. Small quantities of Iron may be complexed with acetic, laotlc, or malonlc acid. malonic. acid.
Low yields m=
result from the uBe of
Amnonlum, potaaslum, and alkaline earths re-
tard the rate of precipitation.
Complexlng Ions such as
oxalate, tartrate, aulfate$ and fluoride In large quant%tiea, also Interfere.
Fluoride Ion may be ccznplexedwith alumi-
-.-
44
PhoaphateO.
Phosphoric acid and sodium monohydrogen
phosphate ,preclpltate U02HP04 from uranyl solutions.
Uranyl
ammonium phosph+te, U02NH4P04j is,precipltated by (NH4)2HP04 or Na2HP04 in the presence of monlum
acetate.
1’ Preclpltatlon
Is made In the pH range 1.2-2.3, 1.7 being optimum. not very Belectlve.
Zirconium,
It Is
bismuth, and thorium preAlkali metals are retained.
cipitate tinder Blmilar condltlonO. Separation 16 made from vanadium.
Both U02HP04 and U02NH4P04
are Eoluble In mineral acids.~ PhoBphate precipitation of uranium (IV) is more Belectlve.
It is made from dilute hydrochloric or perchloric
acid BolutlonB.
Separation 16 made from manganese, Iron,
vanadium and most other elementB.
Zirconium, thorium, and,
to a smaller extent, titanium and tin precipitate. 196-198 Alumlnum lnterfereB by the formation of soluble complexes with With mlfate
uranium and phosphate Ions.~
and alumi~m
present, uranium 16 precipitated In a narrow pH-range around one .
At higher pH, the soluble alumlnum-manlum-phosphate
complex Is formed; at lower PH, the soluble uranium-mlfate complex.
Chromium In exce6s of 0.2 gram
causes incomplete preclpltatlon.—196
per 100 mllliters
Large amounts of fluoride
Ion prevent preclpltatlon.~ Sodium hexametaphosphate uranium
(~)
[(Nap03)6] also precipitates
from acid solutlons.—24o
Adherence to fairly
stringent condltlon.e allows for complete preclpltatlon. 3FJFE104 solution of uranium (IV) Is heated to 60-70”c.
A If
more than 2 mg. of uranium are to be precipitated, a freshly prepared 2$ hexametaphoaphate
solutlon Is added until itB
““
concentration in the preclpltatlng medium Is 0.30-0.35 per cent.
To precipitate smaller amounts of uranium, a 0.5
per cent solution of thorium chlorlde is added es carrier and the hexametaphosphate
added until It la In .exceas 25 per
cent with respect to the thorium, I.e., molar ratio of Th:PO 3 45
is 1:5.
Coagulation Is improved by heating In a water-bath
for ten to fifteen minutes after precipitation. conditions separation is made fram V@Q and other dl- and trl-valent metals.
Under these
and (lW), Fe, M, Incomplete precipitation
occurB with increased or decreaBed acidity -- prmbably becau!e of enhanoed Bolubi,lity of the compound and complex fomation, Precipitation from sulfurlc acid is Incomplete
respectively.
b%cause of uranium-sulfate
~omplex formation.
Under certain
conditions both uranium (IV) and (VI) form complexes with hexametapho8phat e. Hypophosphoric acid
(HUPPOG), sodium dihydrogen hypo-
phosphate (Na2H2P206), and sodium pyrophoaphate
(Na2p207)
precipitate uranium (IV) from acid solutions. +
Other
tetravalent metals, Ti, Zr, and Th, also precipitate.
Separa-
tion i~ made from uranium (VI) and trivalent metals in general. Phosphltee.
Sodium hypophosphite
(NaH2P02) and ammonium
thiosulfate or sulfurous acid precipitate uranium from a boiling, dilute acid solutlon.â&#x20AC;&#x201D;241
Zirconium and titanium
precipitate under similar conditions.
These elements may
be separated prior to uranium by boiling with aodiwn hyposulflte alone.
Elements formlhg acid-insoluble sulfides
are removed with hydrogen sulfide before adding sodium hypophoaphite and ammonium thioeulfate. Sulfates. in
Uranilun (IV) sulfate Is practically Insoluble
47 per cent perchloric acid.
sulfuric acid medi~.
Precipitation is made In a
Uranium is reduced on a mercury cathode
and concentrated perchloric acid is then added. Sulfides.
Ammonium sulfide+ or polysulfide precipitates
brown, amorphous uranyl sulfide.
Numerous
precipitated under similar conditions. ~ mch
other elements are Completing agents
as carbonate, pyrophosphate, and citrate interfere. ~
Uranium (N)
salts are precipitated as U02
s;lfide.~ 46
â&#x2014;?
H20 by ammonium
~
Hydrogen sulfide bubbled through a nearly neutral Bolutlon of uranyl salts containing hexamethylene tetramlne precipitates uranium In a readily filterable, crystalline form of “uranium red. “+
Separation la made from alkali metals and
alkaline earths.= Vanadate6.
Ammonium metavanadate precipitates ammonium
u~anyl vanadate from uranyl Bolutiona buffered with ammonium acetate.—34 ~ .~ .— 242
Uranovanadlc aclda are precipitated at pH 2.2-
Wlthln theoe limits, the composition does not depend
upon the hydrogen Ion concentratldn. vanadium
It doe~ depend upon the
: uranium ratio pre6ent In solutlon.
Compounds
corresponding to the formulae H[U02(OH)2V0310H20,
H[u02(OH) (V03)2]”2H20, and H[U02(V03)3]”4H20
242 have been ldentified.Ammonlum BaltO of theBe ac%dB have 242 been ByntheBlzed In the pre6ence of ammonium chlorlde.— IB the leaBt soluble.
However,
Ita formation 16 a long procei36 at room temperature.
Hea’clng
Ammonium uranyltrimetavanadate
greatly accelerate
Ita rate of formation.
Organic precipitant a.
Organic precipitating reagents
are li6ted alphabetically. 3-Acetyl-4-hydroxycoumarln
(3-acetyl benzotetronic acid).
An alcoholla solution of the reagent added to a uranyl salt 24 6olutlon formB a $ale yellow precipitate insoluble in ethano9 . Precipitation o,ccurB between pH 1.5 reagent precLpltateB.
and 7.
Below pH 1.5
the
The thorium complex iB 6oluble in
alcohol, but precipitates from an aqueouB BOIUtiOn at pH 2-4. Lanthanum and cerium (III) do not Interfere when present in amountB ten tfmeB that of uranium.
Cerlum (IV) lnterfereB
even in small amounts. Acradine.
Uranium (IV) and (VI) are precipitated by
the reagent with the addition of ammonium thiocyanate.—215 Iron (III), cobalt, copper, zinc, cadmlun, mercury, and blB214,216 muth precipitate. 47
216
Aldehyde ammonia precipitates U03.—
Alizarin and Allzarin Red S (sodium aliZarin SUlfOnRte). Uranium Is precipitated slowly by the reagents when the uranyl Ion concentration ia leeB than .20 mlcrmgrams per mllllllter.~ Aluminon (amonium
salt of aurlntrlcarboxyllc acid).
The reagent precipitates both ur~ium
(IV) and (VI) from
216 sulfate Bolutlon8 at PH 3.5.— Aminea.
Ammine salts, generally of the form U02(Amlne)2~,
X Is an acid radical such as acetate, chloride,
where
nitrate, etc. have been prepared from acetemlllde, antipyrene, bromoantipyrine, dlethylaniline, exalgin, nitrosoantlpyrine,
p-nitrosodimethylaniltie,
phenacetin,
Mono-, tri- and tetra-
pyrldine, quinaldine, and quinoline. ammlne salts also have been formed.
pyramidon,
The salts are generally
prepared in anhydrous chloroform or amgl alcohol eolutlona. However, some of the more stable salts may be precipitated from aqueous or alcohollc solutions. 2-Amino
214,244
pyridine precipitates U03.—216
Ammonium benzoate.
Uranyl ion is precipitated by the
reagent from allghtly acidic solutions heated to boiling. A 0.05 ~ Bolutlon of the reagent containing about 2.5$ NH40H is boiled separately and added In an excess of three to four times the uranium present.
Carbonate Ion prevents
quantitative precipitation. 189,245 Ammonium dithiocarbonate
precipitates uranium (VI).
Derivatives also are formed with Al, Mn(II), Fe(II), Co, Nl,
246 CU(II), Zn, Ag, Sn(IV), Pb, and Bl.— Anthragallol forms brown precipitates or solutitms with
U4+, Uoa 2
, Fe3+, ~2+
b .x 9 and Mo C?-
Anthranllic acid. Uranium
Is precipitated from a
solutlon of the reagent buffered with emmonium acetate. reagent added to a 0.1~~(N03)2 4a
solution forms a heavy
‘lThe
The amount of precipitate Is lncreaBed
yellow precipitate.
by the addition of 1~ acetic acid; decreaBed by the addltlon Fifty micrograms of uranyl Ion per
of 1~ sodium acetate.
drop of solution gives no observable preclp”ltate. In acetic acid-sodium acetate buffered solutLonB, slightly soluble salts are formed with the reagent and Mn, Co, Nl, Cu, Zn, Cd, Hg(II),and Pb.~ Arsenic acids.
Benzenearsonic acidt precipitates
uranium (IV) In a weakly acidic solution, pH 1-3. and cerlum (IV) are partially precipitated.
Titanium
Thorium, zir-
conium, hafnlum, tin (IV), nloblum, and tantalum are quantitatively precipitated.~ Arsonlllc acid (p-aminobe~$remlo
actd) precipitates ~ uranium (VI) In a weakly acidic solutlon, pH 1-4 or greater. At pH 2.1 or greater the preclpltatlon Is quantltaklve as evidenced by negative ferrocyanide teOts of the filtrate. Other Ions which precipitate from neutral or sllghtly acidic solutions Include Cu
2+
, Zn2+, Cd2+, and U4+.
With the
addition of sodium acetate, aluminum and ferric Ions alBo precipitate.~ Other substituted arsenic aclda which give difficulty soluble uremyl saltB are 3-nltro-4-hydroxybenzene34 methane-arsonlc aclds.— Bls-benzenephosphomlc
acid.
and
Tests on 50-150 mgfi
uranium (VT) In sulfurlc acid solutions In the presence of approximately 100- to 1000-fold excess ferrous, sulfate, aluminum, magnesium, end phosphate ions gave ne~lY
99$
precipitation with the reagent Optimum conditions for precipitation are pH ~ 25”C, and 10/1 molar ratio of reagent to uranium.~ ~nzenesulftmlc acidic aolutlonB.
acid precipitates uranium (IV) In Iron (III) and the tetravalent Ions Ti,
214 Sn, Ce, and Th also preclpitate.—
49
Benzopurpin precipitates uremlum (IV) and (VZ).~ Benzoylacetone precipitates uranium (VI).~-Bromo-7-carboxy -8-hydro~q uinollne precipitates uranium (VI), copper, zinc, cadm.lum,mercury, and lead.~ ~-Carbo~-8-hydroxy
quinollne precipitates uranium (VT)
In solutlone buffered with acetic acid and sodium acetate. Iron, copper, zinc, cadmium, mercum,
and lead precipitate. ~
7-Carboxy-8-hydroxyq ulnoline precipitates uranium (VI) In ammoniacal tartrate aolutlons. Catechol forms compounds with tetravalent uremium, slllcon, titanium, zirconium, and thorium.~
Catechol combined .wlth
pyrldine preclp.itates hexavalent urenium.â&#x20AC;&#x201D;214 Cresotlnic acid In the presence of sodium acetate precipitates uranium
(l?J)from solution.
Alumlnum and iron
(III) also precipitate.
Separation Is made from Cr, Fe(II), Co, Ni, CU, Zn, Cd, and Mo. 215,216 Cupferron (ammonium nltrosophenylhydroxylemlne) .+
Uranium (IV) Is precipitated from acidic solutions by the reagent.
Good separation Is made from other elemente If this
precipitation follows one in which uranium was kept In the hexavalent etate. from
Ions which are precipitated by cupf.erron
aaidlc solutions Include Tl, V, Fe, Ga, Zr, Nb, Sn, Sb,
Hf, and Ta.
Ions which are not precipitated under such
condltlon.a Include the alkali metals, alkaline ea~ths, &, B as borate or fluoborate, Al, P, Cr, Mn, Ni, Zn,and U(w). Precipitation Is usually made In a sulfuric acid medium but hydrochloric or organic acids may be used.
Nitric acid
should be avoided; aleo perchlorlc acid If the precipitate is to be Ignited. ylamhe
The presence of a reducing agent, hydrcx-
or sodium hydroeulflte, facilitates complete pre-
cipitation of uranium
(IV).
The cupferrate may be filtered
or extracted with an organlo eolvent such as chloroform. ~4,250 â&#x20AC;&#x153;
50
Hexavalent uranium Is precipitated by cupferron from neutral solutions.~ Dibenz OY1 methane fornm a yellow precipitate with uranium
(VI).=
33 5-Dibromo6allcylaldoxlme
precipitates U(VI), Co, Nl,
Hg(II), and Pb.~ b,4’-Dihydroxy-3,5,3
II a
-tetra(hydro~mEthY,l)
-diphenylmethane
precipitates U(VT), Mn, Fe(III), CU(II), and Hg(II).~ Dtiethylammonium dlmethyldithiocarbomate precipitate with uranium Diphe~l
(VI).-
thiocarbgzide
neutral solutions.
formB a red
precipitates uranium (VI) from
Copper (I@, silver, lead, and bismuth also
precipitate with the reagent.—216 Dlpropylamine forms a yellow precipitate with uranium.—216 Disalicylalethylene and (VI).
diimine precipitates uranium (IV)
Most heavy metale are precipitated by the reagent. ~
216 Ethanolamine precipikateO UO .— 3 Ethylenediamlne and uranyl nitrate form am ineoluble double
salt,
U02S04(H2S04)2NH2t2H#~~
acid 6olution.~
In alcolIolio-suM’urio
Double salts of the same type are formed
with piperazlne and dimethylpiperazine.
Siemaae~obBerved
that a solution of ethylenediamine added to a uranium Bolution giveB a bright yellow crystalline precipitate that iB soluble in excess reagent. Ethylenedie.mine tetracetic acid.
Uranium Is precipitated
when a uranyl acetate Oolution Is boiled with solid reagent. @ Gallic acid precipitates U(IV), U(VI), Fe(III), Cu(II~ and ZnG~ Gualacol. A brown precipitate resultB from the reaction of the potasBium salt of guaiacol and uranyl acetate in an a~ueoua Bolution.~ I-Iexamet~ylenetetramine (urotropine)+ iB a weaker baae than ammonium hydroxide and does not abaorb carbon dioxide.
51
This reduces the likelihood of carbonate Interference and of alkallne earth carbonate Pre.clPltatton. Uranium Is precipitated when the reagent 16 boiled in a uranyl solution that contains annnonlum Ion and no exceaa acid.~
Ion8 that fomn Separation can be
stable complexes with uranium Interfere.
made from alkali metals~ alkaline earths, Mn, Co, Nl, and Zn.
Zr, Ti, Fe, Al, Ce(IV), Th, and scme other elements
precipitate. A double salt, U02S04.H2S04” (OH2)6N4, Is formed with the 256 reagent And an excess of sulfuric acid and uranyl salt.— a-Hydroxyacetophenone 216 hexavalent uranlum.— 1-Hydroxyacrldine uranium
forms a white precipitate with
(1-acridol or benzoxine) precipitates
(VI) In neutral solutions.
neutral solutions; Cr(I,II), m(lt),
Mg,Ca, and &
Calcium precipitates from from alkaline solutions;
Fe(II and III), CU(II), Zn, Cd, Hg(I ~d
II),
Te(II), and Pb from solutions containing acetic acid and sodium acetate.
Al, Sn(II), and Bi do not precipitate.~
1-Hydroxyanthraquln!2ne forms slightly
soluble complexes
with uranyl, cobalt, cupric, nickel, magnesium, and man215 ganese ions.— 1-HydroW-3-methoxyxanthone
may be used to separate
uranium, thorium, eerie salts and cerite earths.—258
me
eerie salks and cerite earths are not precipitated by the reagent.
Thorium is precipitated at PH 2.6-4.o.
Uranium
(uranyl ion) precipitates at higher PH. 8 -Hydroxyq ulnaldine. Tetravalent uranium is precipitated by the reagent with the addition of ammonium acetate.
The
precipitation of hexavalent uranium is almost quantitative in the pH range 7-9 buffer.=
from carbonate-free ammonium acetate
Iron, cobalt, ~~kel,
Copperj
chromium are precipitated by the reagent. 8 -Hy droxyquinollne
(oxine).+
52
cadmi~,
and
242
Hexavalent uranium Is
precipitated as UC12(C9H6NO)2 - C91-$N from weakly acidic or baalc ,olutlona.3
Quantltatlve recovery haa been reported
over the pH range 4.1-13.5.
A large number of other elements
are precipitated by oxlne including Mg, Al, Cr, Fe, Co, Nl, Ou, Zn, Cd, Mo, Bl,and T%.
215,260-263
Uramlum can be pre-
cipitated In the presence of small amounta of complexlng agentB: fluorlde, hyd~owlamine, trate.~
oxalate,lactate, and tax-
Separation from small amounts of phosphate also can
be made at pH 10-12 uBing an exce6s of oxine. carbonate interferes.
Ammonium
Tetravalent uranium and oxlne form
a brownish-yellow deposit.~ Isatln-P-oxlme (P-lsatoxlme).+
Uranyl and mercuric
ions are precipitated by the reagent from weakly acldLc solution.
Preclpltatlon Is incomplete but can be made
quantitative by Increaalng the pH with sodium acetate.
A
number of other elements precipitate under these conditions 264 including Fe(II), Co, Ni, Ag, Hg(I), and Pb.—
Separation
can be made from Mn(II), Zn, and alkaline earth l.ons.~ In alkali tartrate solutions, uranium can be separated from 266 cobalt and nickel.— Isojuglone.
The sodium salt of this reagent and uranyl
acetate form a carmine-red precipitate after washing with ethanol.
Iron, cobalt, nickel, zinc, cadmium, mercury, and
lead are precipitated by the reagent.—267 Isonitroso-N-phenyl -3-methylpyrazolone.
Uranyl nitrate or
acetate forms a reddish-orange precipitate tith a 1$ solutlon of the reagent in a 50$ alcoholic aolutlon.
Precipitation Is
quantitative with the addition of Bodiwn acetate.
Mercury (I)
and (II), copper (I) and (II) and uranyl Ions precipitate in acidic media (nitrate or sulfate). Ag, Cd, Nl, Co, Zn, CU(II), and UO~
In acetate solutions, Ions precipitate.
By
reducing the acidity with sodium acetate, salts of Ag, Pb, Bl, Cd, Mn, Ni,,Co, Fe(II), and Fe(III) can be precipitated from
53
nitrate aolutlona.
salts of !IT(l), Sb(III), Sn(II), Al,
Cr(III), and the alkaline earths do not preclpltate.—2t% Lauramldlne hy~rochlorlde.
Thls reagent haa been
248 tested for the aeparatlon of uranium from phosphate Bolutlons.— At pH 2.45, 75$ of the uranium was precipitated. N-Lauryl-lauramldlne.
This reagent also has been teOted
for the separation of uranium from phosphate solutions.
At
pH 2.45, 85$ of the uranium was precipitated. Meroapto-acetic
acid forms a greenish-white precipitate
with tetravalent uranium. w Methylamine precipitates. uranium (W).~ Methyl red causes uranium (Vi) and aluminum h
pre-
clpitate.~ Morphollne precipitates uranium (3W) and (VI) as well as a number of other metal lonB.~
A 1 mg per ml solution
of uranyl nitrate ahowB only a yellow color with the I’eagent. No precipitate la formed.a ~-Naphthoqulnollne
In the preOence of thlocyanate Ion
precipitates uranium (VI), mercury, bismuth, copper, cadmium, nickel, cobalt,.,zinc, and Iron (III) from sulfuric or nitric acid solutlon,.~ Neo-cupferron
(ammonium a-nitrosonaphthyl
is Stillar to cupferron In its application. precipitated by the reagent.—214
hydroxylamlne)
Uranium (IV) is
Nitrilotrlacetic acid forms derivatives with uranium (VI), Iron (III), nickel, and copper (II).m-Nltrobenzoic acid preclpitate~ uranium (TV).fl o-Nitrosohydroxyl amlnophenyl p-toluenesulfonate forms a yellow precipltatie with hexavalent uranium.
Many other me-
tallic Ions are precipitated by the reagent including Al, Cr, Fe(III), Co, Nl, CU(II), Cd, La, Ce, Hg(II), Bi, Pb, and Th.~ a-Nltroso-@-naphthol fine, yellow-orang~to
t
deposits uranium (VI) as a very
broflpreclpltate.
54
Precipitation
Is made In the PH range 4.0-9.4.—272
~eta~~
euch aa Iron,
cobalt, nickel, and copper are precipitated from slightly acid aolutlons. Molybdenum aa.molybdate Ion, zinc, amd uranium (IV) form colored solutlona.—215
Alumlnum, chromium, and cadmium
give no vi81ble reactlon.—215 extracted with myl
alcohol.%
@-Nltroso-a-naphthol acidic aolutlon.
The uranium compound can be
precipitates uranyl ion from elightly
Iron, cobalt, nickel, copper, zinc, and
molybdate Ions also are precipitated by the reagent.
Aluml -
num, ehromlum, cadmium, and uranium (IV) give no visible reactions.
The precipitation of uranium (VT) Is most nearly
complete In an acetate buffered solution. = Olelc acid is a precipitant of uranium (VI). ~ Oxalic acid+ precipitates uranium (IV) from acidic solutlon.—34
Strongly complexlng organic compounds and
fluorlde, sulfate, and large amounts of phoOphate lone interfere.
Uranium is precipitated from 2-3~ hydrochloric acid
media.
At lower acidities other metal oxalateB precipltati,
eg., Fe(II), Zn, Cu.
At higher aclditles the solubllity of
uranium (IV) oxalate increases.
Itiedlate filtration of the
precipitate may result In losses up to lx of the uranium to the filtrate.
Recovery of uranium may be made more quanti-
tative by chilling the solutlon and allowing it to stand. Small amounts of manganese, iron, and nickel may be carried with the precipitate.
Niobium, the rare earths, and thorium
precipitate under slmllar conditions.
If uranium Is reduced
on a mercury cathode prior to preclpltatlon, no catlona In moderate amounts Interfere except rare earths and thorium. Precipitation of uranium can be made in cold 1~ nltrlc
70 grams per liter.
Enough oxallc acid Is added to give a
10$ excess of the amount theoretically required to precipitate U(C204)2.
The uranium then is reduced to the (IV)-state by
.-..
55
adding sufficient rongalite (Na2H2S204”2CH20”4H20) to give a 7-10~ excess of 1 mole of rongalite per mole of uranium. Phenanthrene qulnone monoxlme precipitates uranium (~) and (VI), aluminum, iron, cobalt, nickel,copper, and zinc.= 248 Phenoxarsirrlcacld precipitates hexavalent uranlum.— Phthlocol precipitates U4+, U C?+ p , Zn2+, and MoO~ions.= Picrolonlc acid precipitates tetra- and hexa-valent uranium and most other metalllc ions.> Plperazine. (See ethylenediamlne). Pyrldlnef does not absorb carbon dloxlde llke annnonlum hydroxide does.
This reduces the possibility of carbonate
Interference or of alkaline earth precipitation In a uranium Ammonium nitrate facilitates uranium precipitation.
separation.
Sulfate Ion hinders it.
Separation can be mde
from alkali Zr, Tl, Fe,
metals, alkaline earths, Mn, Co, Ni, Cu,and Zn.
Cr, Al,and others are precipitated by the reagent.~ Pyrogallol and pyrldine combine to form a derivative with 214 hexavalent uranlum.— Qulnaldlc acid+ forms a yellow, amorphous precipitate Preclpltation LIS made from a neutral or
with uranyl ion.-
weakly acidic (PH 2-3) solution In the presence of ammonium chlorlde.
The reagent precipitates a number of metals including
copper, zinc,
cadmi=
and uranium (IV).=
Uranyl ion
Is not precipitated In the presen~e of alkall tartmt~
or
a high concentration of acetate Ion.~ Qulnlzarln (l,!-dlhydro~-anthraquinone)
precipitates
uranium (IV) and (VI), iron and copper.g Rhodlzonic acid forms a blue-black precipitate with tetravalent uranium.
In neutral solutions, &
Hg(I and II),
Tl, Pb, CU(II), Cd, Bl, 21n,Sr, F!a,Fe(II), and U02(II) Ions are precipitated.
At pH 2.8, &,
Hg(I), Tl, Pb,@
are precipitated.~ .,_ ... 56
Be, and 91(11)
Sallcycllc acid. The sodium salt of the reagent forms a greenish-white precipitate with uranium (~).
Under con-
ditions tested, Al, Cr, Fe, Co, Ni, Zn, Cd, Mo~u- , and U&a+ Iorm were not precipitated.~ Sebacaic acid precipitates uranium (lY).fl Sodium,acetate .preclpltateB sodium uranyl acetate from neutral or weakly acldlc solutlono of uranjl aalta.~
The
method Is not very useful for the precipitation of tracea of uranium.
The Volubility of sodium uranyl
acetate In a
aolutlon ~_ In sodium titrate, 1~ in acetic acid, and 0.5~ in sodium acetate Is about 100 mg per liter.—276 (~)
Neptunium
and PlutOnlUM (VI) alSO precipitate under these condi-
tiona.
The addition of sodium acetate and zinc acetate to
a neutral or weakly acidic uranyl salt BOIUtiOII
preclpibatea
the triple salt, sodium zinc uranyl acetate.~ Sodium diethyldlthiocarbamate
precipltatea tetravalent
uranium, aluminum, iron, cobalt, nickel, copper,and cadmium.~ Hexavalent uranium may be precipitated when both uranyl and reagent ,concentrationa are aufflclently large.Sodium ethyl xanthate
form
an orange precipitate
with uranium (VI).St-rychnine In the preoence of fluoride Ion precipltateO hexavalent uranium as 7(C21H2202N2HF)
“ 6(U02F2) “ 2HF.
The
volubility of the preclpitatel In water at 25”c 18 47.5 mg/100 ml; in 60Z alcoholic solution at ZP”C, 30 mg/loo ml.~ Tannlc acid (dlgalllc acid)+ and tannin (a glucose ester of tannlc acid)+ react with uranium (VI) to give a deep-brown preclpltate.—34
ElementB arranged according to decreasing
ease of precipitation by tannin are Ta, Ti, Nb, V, Fe, Zr, ~; Th, U, Al.-
The position of chromium In this series is
uncertialn. Tantalum, titanium, and niobium may be separabed by tannin ln~.a slightly acidic oxalate ❑olution.
Uranium and
otherB are precipitated by adding more tannin and by making
57
the t301utlon ammoniacal.
Uranium may be precipitated from
such solutions In the presence d mbona%acetate,
or tartrate
Ion..= Thloslnamine. Uranium and cadmium are precipitated when “an alkaline aolutlon containing theee elements 18 boiled .wlth the reagent.= Carriers.
Trace amounts of uranium may be removed from
solution by the use of gatherimg agents or carrler~.
The
choice of a particular agent depends upon the conditlonB under whtch precipitation la to be made amd upon subsequent chemistry to which the precipitate Is to be sub~ected. Rodden and Warf~
have described the application of Oeveral
carriers: ferric, alumlnum, and calcium hydroxide.
The use
of barium carbonate and thorium hexametaphosphate has been mentioned In the section on inorganic preclpltants.
Mag-
nesium oxide and thorium pm.’oxlde have been used. 2
The
oxide and salts of anttionys
281,282
calclum fluorlde,fl
and the phosphates of zlrconlum, ~blsmuth,=
and thorl~>
—24CI have been u8ed to carry uranium from reduced solutions. Uranium (IV), In general, should behave slmllarly as neptunium (IV) and plutonium (IV).
These are carried by
lanthanum fluoride, eerie and zlrconlum Iodates, eerie and thorium oxalatea, barium sulfate, zlrconlum phosphate, and bismuth drsonate.~
Uranium (VI) does not carry with these
agents providing the concentration of either carrier or uranium Is not too large. Complexes.
The preclpltatlon of uranium In normally
preclpltatlng media Is Inhibited by the formation of soluble complexes. ~
Carbonate Ion is a very efflclent
complexlng agent of uranyl Ion.
In armnonlti hydroxide
solutlon, uranium can be Beparated from iron, tltanlum, zirconium, and aluminum with carbonate ion present.
In ammonium
sulfide solutions, carbonate Ion makes possible the aepsratlon 58
of uranium from manganeOe, Iron, cobalt, zinc, and titanium. Ammonium oarbo.nate prevents the precipitation of uranium with phosphate.
Precipitation with sodium carbonate makeB possible
the separation of uranium from beryllium, manganese, iron, cobalt, nickel, zino, titanium, zirconium , and the alkaline earthe. Sodium peroxide facilitates the i3eparation of uranium aud other metals with sodium carbonate.
The addition of the per-
oxide alone to aoid EolutionB of iron, cobalt, rare earths, titanium, zirconium, hafnium, and thorium causes their precipitation while uranium, if present, remains in solutionâ&#x20AC;&#x2122;. Uranium does not precipitate with tannic acid in acidic solution with oxalate ion present.
slightly
Titanium, niobium,
tin, tantalum, and tungsten are precipitated under such conditions.
Oxalate ion aho
interferes in the precipitation
â&#x20AC;&#x2DC;
of uranium by ammonia. Tartrate, citrate, and malate ions prevent the precipitation of uranium by amonium
hydroxide or sulfide. ~
Salicylic acid and hydroxylamine have both been used to complex uranium in separations from rare earth elements.
&
Hydroxylamine has been used in separations between uranium and beryllium, aluminum, iron, and thorium.~ Completing agents that form weak complexes with uranium and relatively strong complexes with other metallic ions make separation pcssible between the two: uranium is precipitated by a suitable reagent; the other ions remain in solution. Ethylenedlaminetetracettc
acid (complexone II) and its
disodium salt (complexone 111) have been used successfully in this respect.
Uranium has been precipitated with
ammonia In the presence of complexones without Interference from Al, Cr, Mn, Fe, Co, Nl, Cu, Zn, Cd, La, Ce, Hg, Pb, Bl, .. . and the alkaline earths.â&#x20AC;&#x201D;284 The recovery of uranium is not entl~ely quantitative since the completing agent Increases the solubillty of the monlumur~ate.u 59
me
absorp-
tlon of impurities in the preaipltatie may necessitate dissolution and repreclpitation of the uranium. =
Berylllum
.286 and titanium follow the uranium chemistry.— Quantitative recovery of uranium from the aforementioned cations: Al, Cr, Mn, Fe, etc., can be made with ammonium monohydrogen phosphate, tNH4)2HP04, in the presence of ethylenedlamineketracetic
acid.~
Beryllium and
titanium again interfere.
Small smounta of t-ltanlummay be
compl,exed with hydrogen peroxide before the addition of 287 other reagents.— Sen Sarma and Mallik~
have studied the separation
of uranlwn from other elements uahg
8-hydrwxyquinollne
(oxlne)
as precipitant and complexone III as complexlng or masking agent.
It was found that complexone had no masking action
on uranium In the pH range 5-9.
In a solutlon buffered with
acetitc acid and annnonlum acetate at pH ‘5.3 quantitative Beparatlon was reported between uranium and Al, Mn, Fe(III), Co, Ni, Cu, Zn, Zr, Cd, rare earths, Pb, Bi, Th, and P205. In ammoniacal medium at pH ‘8.4,a
similar
sepairatzon
frmm V205, M003, and WO ‘ Steele and Taverner,~ 3“ were unable to dupllcate the above results. 2.
Solvent extraction.
W~S
~de
however,
The solublllty of uranyl nitrate in
organic solvents has long been recognized.~
The ability
of dlethyl ether to extract this salt has been used In systems of analysis for many years.
However, it Is only
wlthln recent years (starttng in the 19401s) that widespread use has been made of solvent techniques as a means of separating and purlfylng Inorganic substances in general
2%?32
191,192,194,197-199,3 00-305 and uranium In particular. The conditions under which uranium may be extracted are many and varied.
In the present paper, extraction from
aqueous solution Is considered. solid phase~
and slurrie~
60
However, extraction from has been Investigated
and a favorable uranium partition haE been found.
Conditions
which affect the extraction of uranium from aqueoua Eolution by organic solvent are the Composition of the aqueouB phaOe, the nature of the organic pha6e, the temperature, and the time of equilibration. as uranium,
In the aqueous phaBe, euch factors
acid, conmon anion, foreign anion, and forei~
cation concentration must be conaldered.
The nature of the
organic phase dependa upon the type and concentration of Bolvent and dlluent.
If the organic phaae la not Initially
barren, lt6 concentration of uranium, acid, etc., affect6 partition. BecauBe of the number of varlableB and the large number of uranium solvents, one cannot consider, in a volume of this size, each solvent In the light of each variable.
Indeed,
the behavioral relatlon between solvent and the afore-mentioned variables Is known for only a few well-studied
solvents.
The purpose of the present paper is to provide Information on the conditions best-suited for the quantitative extraction of uranium or for the separation of uranium from interfering elements.
This is done as much as possible in graphic or
tabular form. The solvents are dlvlded Into five general classlficatlons: 1) ethers, esters, ketones, and alcohols; 2) organo-phosphorous compounds; 3) amlnes and quaternary ammonium OaltB; 4) carbo~llc acids; 5)
chelating agents.
Dialkylphosphorlc
acids, eg.,
dibutyl phosphate, are ,classified as organophosphorus cornpounds rather than chelating agents.
Carboxyllc acids are
classified as such,although some may also be considered chelating agents, eg., sallcyllc acid.
A number of extrac-
tants may serve also as diluents or seconda~ other extractants. primary extractant. is described under
solvents for
Such systems are described under the For example, a cupferron-hexone syEtem “cupferron” rather than under “hexone!’ 61
‘
In the dlacuseion, the terme “extractant” and “solvent” are often used Interchangeably.
“Dlluent” 10 used to deacrlbe
a secondary solvent rather than the term “Inert solvent. ‘~ The choice of diluent may appreciably affect the partition of Uranium .
A number of temna that
are frequently used are
defined below. Part;tlon or extraction
coefficient:
concentration of a substance In the organic phaae concentration of the same aubatance in the aqueoua phaae
a=$= a
Percentage extracted: P = .&
x 100, when equal
volumes of both phaaea are present
after ahaklng. Maae ratio: Z
V. amount of a aubetance In the organic phaae = amount of the same aubatance In he aqueouB = a ~ a phase Separation factor:
concentration of aubatance ’A In the organic phaa~ concentration of substance in the organic phaae concentration of aubBtance Ai n the aqueoun phaae ——. concen~~i~of mbBtance B in he aqueoua phaae -~uilibrium laws.
.— ‘A %
The phyaioal chemical principles
involved in the solvent extraction of uranyl nitrate have been summarized In references 308-312. Detailed methods of treating the variouB equLllbria involved have been devised.111’313-315
A more simple approao~.adapted from a
paper by Carleso AIL ,
la herewith presented.
It may be aasumed that within a certain concentration range an average uranium complex la extracted.
The complex
is representative of a whole aet of complexes and may be written 3 may be U+
M(+X)L
(x+y)(~”)h “ (S)n. #x, in thla case, or UO+2 L, as written, 16 a Blngly, negatively 2“
charged ligand.
It may be more highly charged.
a eolvent molecule. Integers.
S represents
The subacrlpts y, h, and n need not be
The reaction for the extraction mechanism may be
written
62
F#xaq + yH+aq+
(x+y)L-aq + ns org~ v(~+~)sn%okorg
+ m20.
The thermodynamic equillbrluq copatant for the reaction Is m [Hyqx+y) Sn(H20)hl org !+20 K= > [M+x] [H+ly [L-][x+y~ [Sl&g “ f(7) r and [ ],respectively, re~reOent the activity and t} concentratlo~ of a quantity In the aqueous phase unleB6
where
otherwise identified by the Bymbol “org.“
f(y) represents
the product of the activity coefficients.
The partltlon
coefficient is approximated by ~E a==
‘L(~+y)sn
(HO) 2 h ]org .
.—-] [M-rx
The relation between the partition coefficient and equilibrium constant is log a = y log[H+laq + (x+y)log[L-]aq + n l.og[S]org -m log
{1 ‘~0
+ log “T(y) + log K.
Information concerning the extracted species may be obtained by measuring the partition coefficient while varying the concentration of only one of the quantities.
A knowledge of
the activity coefficients is then required or the product of the activity coefficients in both phaBes must be kept constant. As stated previously, the above approach to solvent extraction is a simplified version. average extracted species.
It represents only an
Among other things, it does not
con~lder the effect of water activity In the organic phase, solvent activity in the aqueous phase, complex formation between the various components in either phase, or the formation of polynuclear species.
These effects may be large or small
depending upon the eolvent, aqueous medium, and uranium concentration involved. ETHERS, ESTELS, KETONES, AND AWOHOLS.
Uranyl nitrate
Is extracted by many polar solvents which contain donor oxygen atoms such as ethers, esters, ketones, and alcohols.~
63
ExtractIon from water 0olutlon8 Is small unleaa the uranium concentration ia ,appreclable.
ThIa 18 ahown in figures 1-5
in which the data of McKay and co-workers, and Veael$, et al= obaerved~
are plotted.
warner,~
In general, it haa been
that:
1) the extraction coefficient of uranium decreaaea when the number of carbon atoms Increaaea for a gtven homologous aerlea of organic eolventa, 2) for a molecule with a given number of carbon stoma and a glyen chemical functlor@
group, aolventa with atralght
chains are more efficient extracttita than those with branched chaina, 3) one or more double bonds h
a molecule Increases the
efflclency, L) primary alcohola are more efficient than seconda~ ones, 5)
the coefficient of extraction Increaaeo with the
aolublllty; but there la no well-defined relation between the two. Evidence considered in the aectlon on non-aqueous aolutlona Indlcatea that uramlum Is extracted from aqueoua nitrate aolutlons aa hydrated, aolvated uranyl nitrate, U&@3)2(H20)h~,
.
Under appropriate condltlona, the
hydrated, solvated trl~trate-uremyl
complex may be extracted.
The relatlonahlp between partltlon coefficient and equilibrium constant for the extraction mechaniam ahowa the extraction of the former speclea to be favored by
large free nitrate and
free solvent concentratlona and by small water activity. Effect of nltrlo acid.
The addltlon of nltrlc acid to
the aqueous phaae favors the extraction of urenlum by preventing or decreaahg
thehydrolyala
of uranyl Ion and by
Increaelng the nitrate Ion cono.entratlon.~
Nltrlo acid
la extraoted alao by the organic aolventa.
This requirea
64
0.5
3
/Y’1z -;
8/
0.3
jf/’
2
0.2
i
I 0.I
I
o o
I-.2 URANYL
3
MO LALITY (A)
(~qu@Ou@ pha61~)
4“
0.1
0.2
GRAM OF GRAM
0.3
0.4
0.5
LJRANYL NITRATE Der OF AQUEWS PHASE (B)
Figure 1. Partition of uranyl nitrate between water and simple ethers. 0, diethyl ether. A, ethyl-n-propyl ether. ❑, ethyl-n-butyl ether. V, di-isopropyl ether, B, di-n-butyl ether. A, di-n-hexyl ether. ❑, 2,2’ -dichlorethyl ether. l-A. After E. Glueckauf, H. McKay, and A, Mathieaon, reference 185. Temperature, 250C except for diethyl ether: first three points at 25°C, laat point at 20°C, remainderat 180c. l-B. After R. K. Warner, reference 321. Dashed curve represents the partition of uranyl nitrate between diethyl ether and a saturated ammonium nitrate solution. Temperature, 200C,
0.6
I
I
I
I
I
I 0.1
0.2
0.3
0.4
0.5
0.4
0.3
0.2
0.I =a *C+ lx 0
0 0
I
o
URANYL
f?
MOLALITY
3
(aqueous phase)
4
GRAM OF URANYL NITRATE per GRAf14 OF AQUEOUS PHASE
(A) Figure 2. Partltlon of uranyl nitrate between water and complex ethers. A, dlbutyl cellosolve. v,V, dlbutyl carbltol, H,n, pentaether.
(B) 0, phenyl cellosolve.
2-A. Open symbols, after E. Gleuckauf’,H. McKay, and A. Mathleson, reference 185. after A. Gardner, H. McKay, and D. Warren, reference 176. Temperature, 25°C. 2-B. After R. K. Warner, reference 321. Temperature 200C.
Solld symbole,
6
.
c1
I
URANYL
2 P40LALITY
3 (aqueous
4 phose)
Figure 3-A. Partltlon of urenyl nitrate between water and Isoamyl acetate. After E. Glueckauf, H. McKay, and A. Mathleson, reference 185. Temperature, as”c.
GRAM OF URANYL NITRATE per GRAM OF AQUEOUS PHASE F’fgure 3-B. Partition of uranyl nitrate between water and nitromethane and saturated ammonium nitrate (dashed curve) and nltromethane. After R. K. Warner, reference 3’22. Temperature, 20°C.
67
4
I
I
I
1
I
1
t?
.MHC
0
0.1
I
I
I
[ n
3
--
0 0
0
2
I URANYL
MOLALITY
3 (aquoouo
0)
phose)
4
.
A
-
GRAM
6k OF
GRAM
- 0,
URANYL
6 NITRATE
OF AQUEOUS G)
POr
PHASE
Figure 4. Partition of uranyl nitrate between water and ketoneB. O, methyl ethyl ketone. O, methyl Iaobutyl ketone. A, methyl n-amyl ketone. A, dl-lsobutyl ketone. ❑, cyclohexanone. MHC, methyl cyclohexanone.
,
4-A. titer E. Glueckauf, H. McKay, and A, Mathieson, reference 185. Temperature, 25°C. 4-B. MHC curves, after V. Vesel$, H. Beranov4, J. Mali, reference 323. Dashed curve--aqueous solution, 6~NH 4N03. Remaining curves, after R. K. Warner, reference 321. Temperature, 20°C. Ikshed curve--aqueous solution, saturated ammonium nitrate.
3
2
-1
“o
2
I
0
URANYL
MOLALITY
4
3
(OqueOu S phase)
(.4) B
I
I
I
1
1
1
0.4 #i 0.3
0.2
0.1
a
C5
0 o
0.1
“0.2
1
1
1
0.3
0.4
0.5
! 0.6
GRAM OF URANYL NITRATE per GRAM OF AQUEOUS PHASE m) Figure 5. Partition of uranyl nitrate between water and alcohols. ~, n-pentanol. A, n-hexanol. V, methyl Isobutyl O, n-butanol. carblnol. ❑, iaoamyl alcohol. E, sec-octyl alcohol 5-A. After E. Glueckauf’, H. McKay, and A. Mathieson, reference 185. Temperature, 25°C. 5-B.
After R. K. Warner, reference 321.
69
Temperature, 20°C.
that It be replaced In contlnuouO or multicontact extraction process.
Large concentratlorm of nitric acid are generally
The formation of HI?O . Sn complexes reduces 3 the amount of free solvent, the extraction of other elements
not dealrable.
is enhanoed, and the dhger
of an explosive reaction between
solvent and acid is increased.
The formation of HM(N03)X+1
species, which may be more easily extracted than M(N03)X, For u.ranlm,
iB promoted by the addition of nitric acid.
however, the formation of the trlnltrate-uranyl complex Is far from complete, even in 16 g HNO .~ 3 Effect of nitrate salts. The pltrate Ion concentration may be Increased by the addition of metal nitrates of Slgnlficant This not only promotes the
volubility to the aqueous phase.
extraction of uranium but also the extraction of other elements whose nitrates are soluble .In the orgsnlc solvent.
In some
cases, nitrates which serve as saltlng-out agents, eg. thorium may also be extracted In Blgniflcsnt amounts.
The extraction
of other salting-out agents, @g., ceslum, may be enhanced by the formation of uranyl trinitrate complexes, MUOO(NO=)Q.~ c
The ablllty of varloua nitrates to
salt-out uranium has been
related to the hydratfon of the cation,~ coefficient of the pure nitrate salt,= and charge of the cation.~A
JJ
the activity and the radius
salting-out agent which Is
highly hydrated facllitatea extraction of uranium by reducing the water activity.
In figure 6, the partition coefficient
of uranium is plotted as a function of alumlnum nitrate for several solvents.
The partition of uranium between
saturated armnonlum nitrate oolutions and diethyl ether, nitromethane, and methyl ethyl ketone Is shown by the dashed curves in flgurea lB, 3B, and 4B, respectively.~ Ammonium nitrate is widely used as a salting agent in spite of its relatively poor salting-out ability.
The ease with
which it is removed from solution or from heated samples 70
1.0 ~
I
I
I
1
I
I
0!i?34567~
EQUIVALENTS
I
I
I 9
OF
Al (N03)3
I
I
I
10
II
12
par 1000 CC OF HzO
Figure 6. Effect of aluminum nitrate as salting-out agent on the extraction of uranium by various solvents. Curve 1, dlbutoxytetraethylene glycol (pentaether); Curve 2, dlbuto~triethylene glyc~l; Curve 3, dibutoxydlethylene glycol (dibutyl carbltol); Curve 4, methyl Isobutyl ketone (hexone)~ Curve 5, diethyl ether; and Curve 6, dibutylmonoethylene glycol (dibutyl cellosolve). Data adapted from E. Evers and C. -US, reference 332. Conditions: Aqueous phase - 2.o to 6.o grams of u per 100 cc of solution containing aluminm nitrate. Organic phase - solvent represented by curve, Equal phase volumeB* equilibrated at 27°C. *Equal or approximately equal phase volumes were employed in distribution expertients with dibutyl carbitol (C. A. Kraus, A-2322(1945)) and with hexone (C. A. Kraus, A-2324(1945)). It Is assumed that the â?&#x2018; -e volume ratio was used for other experiments.
71
makee Its uae advantageous. The presence of nitrate Balta which are sufficiently soluble In the orgamic solvent facilitates the extraction of uranium by formation of the trlnltratouranyl complex, RU02(N03)3.~
This Is discussed further under ‘!Hexone. ”
Effect of other aalta.
Anions that complex uranium
in the agueouO phase may seriouuly Interfere with the extraction of the latter.
Chlorlde, fluorlde, sulfate., phos-
phate, and several organic anions have been studied for their interference.
The adverse effects of these Ions may
be mdnimized byranoviqg them fbomsolutlon “piortoura”nium
ex-
traction, by completing the anions with cations of Saltingout agents, or by using sm excess of an efficient aaltingout agent to over-ride the anion interference.
The inorganic
anions may be precipitated as silver ohloride, lanthanum fluoride, barium sulfate, zirconium phosphate, or ammonium phosphomolybdate. and CalCi~.
Fluoride ion is complexed by aluminum
Sulfate ion is complexed by ferric ion.
Large
amounts of sulfate ion are also precipitated by calcium nitrate. iona.
Phosphate ion is complexed by ferric and aluminum
Calcium n$trate ha~ been used ta counteract the effect
of acetate and oxalate.
The effect of chloride on the
partition of uranium may be reduced in the presence of a strong salting-out agent.
Chloride ion is more objectionable
from the fact that it promotes the exbractlon of other elements, notably iron.
In the presence of large amounts of interfering
ions, particularly sulfate and phosphate, it is advisable to separate the uranium from solution prior to extraction.
This
may be done by pre.clpitiationwith carbonate-free ammonium hydroxide.
The precipitate is dissolved in nitric acid and
the extraction is initiated.
Ferric hydroxide may be used
to carry trace smounts of uranium. Uranium may be extracted ihm 72
aqueous medta other than
nitrate.
Thlocyanate solutions have been found satisfactory.
The ext=ctlon,
however, ie le68 aelectlve from thiocysnate
than from nitrate solutions. Solvent action.
The partition of uranyl nitrate is
dependent upon the free solvent concentration.
ma
la
reflected in the coefficients of exlmactlon of micro macro
and
amounts of uranium from highly salted aqueous solutlone.
‘lThe partition coefficient of trace imounts is larger thm that of large amounts as a result of more available solvent. As mentioned previously, macro amounts of uranium extract more readily from water solutions or less highly salted aqueous solutlons than do micro smounts.
This effect may
be attributed to the salting-out ability of uranyl nltmte itself. The extraction of other elements iB affected also by the uranium concentration.
High loading of the solvent
by uranium reduces the extraction of less preferred complex species.
High uranium’loading may be achieved by diluting
the solvent with a secondary solvent in which uranyl nitrate is insoluble or significantly less soluble than in the primary extractant.
Solvent dilution, in general, causes a deorease
in the partition coefficient.~lg’3 Sautero~
21,329,3
30 Wohlhuter and
have listed a number of aromatic and chlorine-
substituted dlluents in order of increasing harmfulness to uranium extraction: benzene, toluene, xylene, carbon ,tetrachloride and dichloroethylene,
chloroform.
Solvent dilution
may be used also to improve upon the physical propert~es of the organic phase, eg., density, viscosity, etc. The suitability of mixtures of oxygen-containhg Bolvents as extractants for uranyl nitrate has been Studied.318-3Z’0,329,330 .
Stover and co-worker=
reported
that none of the mixtures they Investigated were better than the pure solvent.
Recenbly, however, Fomin and tirguno a
73
I
and Vdovenko and KrlWkhatskll~’have
reported enhanced
uranyl titrate partition coefficients from t301ventmixtures. Vdovenko and Krlvokhatskll repofi that over ten such mlxturea have been found.
Among them are:.di-laopropyl
ether and f3, @’-
dlohlorodlethyl ether, dibutyl ether and t3,P’-diohlorodiethyl ethers dletwl met&l
ether and acetophenone, Isoanwl alcohol and
Isobutyl ketpne!. The enhanaed extraotlon by solvent
mixtures hae been attributed to the formation of mixed aolvatea of uranyl nitrate.~ Effeot of temperature.
The extraotlon of uranyl nitrate
ia decreased by a te~erature
Inorease.
The pertltlon co-
eff’iotent of uranluni Is plotted as a function oi!temperature for several. solvents In figure 7.X .—
Figure 7. The effect or temperature on the extraction of uranium by 0, dlethyl ether. organic solvents. O, dlbutyl carbltol. ❑, hexone. & pentaether. Mter E. C. Evers and C. A. Kraus, reference 332. lea represent aqueous solutions Baited with 36.6 gramm The trl of Al(NOY 3 per 100 cc of water. All other symbols represent solutionB sa ? ted with 58 grams of Al(NO )3 per 100 cc of water. 2 to 6 grams of uranium per 100 cc of SOIU 2 ion were extracted.
74
ge-extraction. UranlUm 16 re-eXtr6K3ted frOm the organic OolventB conaldered fn thlB BeatIon by Contaot with water.
Several water contaats may be required if large
amounts of uranium or nitric acid have been extracted. Watersoluble salts whose anlona complex uranyl Ion, eg., ammonium sulfate, facilitate re-extraction. ExtractIon of other elements.
A number of ,elements
other than urenium are extracted by oxygen-containing vents.
Bol-
Those commonly found with Irradiated uranium me
hexavalent Np and Pu*; pentavalent Pa; tetravalent Th, Np, Pu, Zr(+Nb), and Ce; and ruthenium complexes.
Neptunium,
plutonium, and oerium are made less extractable by reduution to lower oxidation states. from the other elemsntx
Fawrable
separation of u?.%nlum
may be achieved by control.of the
nitric acid and saltlng-out agent ooncentratlons. halogens are extraoted.
Free
These elements may be ellmlnatdd
from solution prior to uranium extraction.
The halogens
also combine chemically with a number of solvents; eg,~ Iodine and hexone.
The combined halogen Is not re-extracted
by water contacts. General survey.
The extraction of uranyl nitrate w
polar oxygen-containing a variety In
Or
conditions.
solvents has been Investigated under me
~sults
.whlch the .experlmental condltiom
Or three SUIâ&#x20AC;&#x2122;WY_ were all differen~ are
given In Table VIZI.
*
Am(VI) forms an extractable nitrate. Strom oxidizing conditions are necei3sary, however, for amertcium to be present in the (VI -state. It is genelâ&#x20AC;&#x2122;ally found in solution as Am(III 1 . 75
Mmt+lbution of Umny 1 Nltm3ta-tueen Vtiuua OZrmn -cant~ng
Table wZI.
~w ~ m
STOtal VOlulw org. layer
●
901v’ent 0
rvey
m
*
1
m DIethyl
@
ether
n-Pivpyl Inoprowl Ditityl
17
61.5 56.5
84
100
63.3
99
lm
66.6
<1
2thyl n-butyl
athar
Bm6yl
ether
methyl
B-B’-DiWoroet~l
Ethyl
57 00
20
“ethmr ethnr
Dieth@
45 49 41 37
62.5 35 50 53.5 55 55 53.5
1.1
ether
ethe
<1 e <1
.a.sJlomlve tutyl
Dibutyl
Calloenlva
anllosolvm
Fllwl
aellOBOlve
%nxyl
oollomolve
Ditityl
carbital
m
0.0 35 2.2 0,0
0.1s$ 0.10
1.6 0.0
0.05
55 59
0.09
0.00 0.00
0.29
24. 7
0.01 O.w 21
59
P.7
0.15?
0.09
0.54
g~~~n~;~w$e
34
mlmthyldlo%an-s
3.E
W
-r “5
2thylaoetite n-PrO@
acetate
Impropyl
aaetate
n-Eutyl
acetate
6
ncehte
2 -Ethpllmtyl 2-EtFw$
%.5
acetate
~lacetite
oarbitol
alycol
59
aaatata
Ieabutyl
Wtyl
,6
aontate
aeo-~tyl
Am@
65 @
92
acetate
:1 15
U3 w 54 39 39 21 31 9
0.6
0.2+
1.3
9.1
1.2
11.9
0.06
10.6 22.2
0.02 0.3
0.18 31.9*”
0.02
54 67
95
0.25
diaoetate
0.11
Ett@aceto80etnte Methyl
plwprlonate
2thyl proprionate Ethyl htymte Ethyl
a-brm.otitymte
Methyl
75 42,
-3 3
54 m
!n.5 9
0.06 0
7.5 o“
bnzoata
Ethyl bmzoate Ethyl
6, :1
10-20 0,2 2-2 0,03 10 0
capmate
%.5 55 0.07
Diethyl
mleate
met~l
malonats
22
Ketone l— n
Methyl n-prowl
‘“%X%Nethyl n-amyl
ketone
‘ebn’ ketirm
47 53
22
57 b~
20
11
0.9
20.9? 30+
0.02 0.01
Uethgl n-hexyl ketone Diathyl
0.004
O.m
ketone
%
70
0.3
42.7+
Table
VIII.
- Continual
I
$ Total
Solvent
volume In org. layer
Th
●
0.05 0.80
11 ~m
Cycloh8~one Fethyl
cyolohexanone
m-Methyl
cyolohexnnone
p-Methyl
ayclohexancme
o.2b 0.9
63
77.6
!Ienityl oxide
0.53
0.24
12,7 27
Iaopt.omme
#Jcohola n-~tanol 2-Ethyl
5.2
30
0.6
0.01
❑ea-Eu5Y1
oarbtil
tert-Amyl
aloohol
Diethyl
63
oarbinol
,~i-n-tutyl
oarbinol
nexanol
2-Kthyl
5.6 51 10 77.5
n-OotanOl
24
0.7
11,
0,0
0.0
72.1
24
0.65
71.5*
54 56.5
FAptanol E-amyl
36-9
oarbimal -
Heptndeoar.ol I 2 -Bthyliexanaiol-l
0.013++
61
oarbinol
D1lEOWUPY1
Methyl
44 butanol
4,? 0.5
74.8
0.0
?ll.? 0.09
,3
Mimellaneoum 32
Nitromethane
54
62
0.00
,1-Nltroprnrmne
3.
lw.ae
0.25
Nitrobensena
2.
Traae
0.10
o-NltrvaniBOle
3.’
Traaa
0
MIOWO-
0
o
0
TriOhlOroet@lene
1.
0.2
chloroform.
0
0
12-Nitr-Opmrmne
thnne
l.a
3Lmethglmilfa10n0
●
itiioaten
mutual
volubility
of waueoua
tilution
.9.D4o-o
77
nolvent.
ETHERs “Dlethyl ether “Agueoua nitrate syBtems. ----- ---------------
The extraction of uranyl nitrate
by dlethyl ether 18 widely ueed in radiochemlcal aeparatiolm becauee of the selectivity of the extraction.
Disadvantages
of the method are the high volatility and low flash point of the solvent and the relatively “low distribution of uranium into the solvent. The partition of uranyl filtrate between diethyl ether and water is illustrated in figure 1.~ phases saturated with uraqyl nitrate trlbution coefficient is about 0.68.~
with both
at 25-26”c, the diBThe effect of nitric
acid upon the partition of urani ~and.nitric ~
itself is represented in figure 8.
and Morrlson@repmt
acld~’ Furman, Mundy,
that the pH”of the aqueous phase
should be ~ or less for aomplete extraction of uranium to occur.
!l%e influence of ammonium titrate and calcium nitrate
upon the extraction of nltrlo acid is alao shown in figure
Figures 9 and 10 demonstrate the influence Of .VEmiOUi3 saltlng-out agents on <he distribution of uranyl nitrate.The nitrate concentration plotted in figure 9 includes that of the salting-out agent plus that of uranyl nitrate left after extraction by an equal volume of ether.
The latter
contributes only a few percent to the total nitrate concentration
in most cases.
point at 1.18PJ
A notable exception is the iron[II~)
nitrate concentration.
In this Instance,
0.82~ nitrate ion is attributable to ferric nitrate and the remainder to uranyl nitrate.
The nitrate concent=tlon
of the salting-out agent is plotted in figure 10.
Uranyl
nitrate contributes little to the nitrate concentration since only one gram of uranyl nitrate was used per 100 grams of initial aqueous solutlon.
Furman, Mundy, and Morrlso s 78
I 10
I
I
I
I
I
I
I
I
I
I
[v=--’
HNo3-co(No3-)~
. HN03-NH4N03
. . . . . ..~-.o]u~(N03)2-
+
1.0
HN03 :
D
/ 1] 0.1
F
-.
~ch
0.01
1
I
I
I
I
I
I
012345678 INITIAL
I
I
I
I
9101112 AQUEOUS
NITRIC
ACID
CONCENTRATION,
M
Figure 8. The extraction of uranyl nitrate and nitric acid by dlethyl ether. Uranyl nitrate extraction: 0, after R. Beck and E. Bock, reference 333. Inltlal U concentration, O.lM; Temperature, 200 ~ 1°C; Vofla = 1. Dashed and dotted curves, a?ter J. Kool, reference 334. Temperature, 25°C; Vo/Va = 1; Initial U concentration, -----------50, 150, 450 mg uranyl nitrate (hexahydrate) per 15ml; ...........1350 mg uranyl nitrate (hexahydrate) per 15 ml. Nitric acid extraction: O, after R. Bock and E. E!ock, reference 333. Temperature, 19° + l°C; Vo/Va = 1. 0, after J. Kool, reference 334. Temperature ,– 25.0 ~ o.locj vo/va = 1. 0, after A. Grlnberg and G. Lozhklna, reference 335. Temperature, 20°C; Vfla = 1. A,V,V, after N. Furmsrl, R. Mundy, and G. Morrison, reference Vo/Va = 1; HNO ~4H20 per 100 ml of initial SOIU Ion %%&, 1Ro;;0&$?J2 O E. of NH4N03 per 100 ml of Initial solutlon plus 3“
79
I 000
I
1“
I
I
I
I
I
I
i
d
I
I
500 200 I00 50 20 10 v-y
5
i
2 I 0.5 0.2 t o. I 0.05
0.02 0.0! NITRATE
2
3
4
5
CONCENTRATION
6
7’ OF
8
AQUEOUS
(See facing page for legend. )
80
9!01112 PHASE,
M
117. Figure 9. Effect of varlouB nitrates upon the partltlon coefficient of’ uranium with dlethyl ether. After N. Furman, R. Mundy, and G. Morrison, reference 326. The nitrate concentration plotted aa the abBclBBa lnclude8 that attributable to the equilibrium concentration of uranyl nitrate In addition to that of the Inltlal concentration of salting-out agent. Conditions: Saltlng-out Agent NH4N03 NaNO
3
LiNO
[UJ, .@
T.°C
25
25-6
1
(25)
24-6
1
’88
1
(2s)
3 Ca(N03)2
(25.-100)
25-29
1
~(N03)2
(2s-100)
27-28
1
(50)
28-31
1
Zn(N03)2 ‘(N03)2
(-8->600 )
Fe(N03)3
(-8->200 )
A1(N03)3
(25-100)
Th(N03)4
(50)
1 29
1 1
The uranium concentratlone In parentheses have been estimated by roughly adding the equilibrium uranium concentratlonB of both aqueous and solvent phase.
81
Ni+4
0.0!
GRAM 1000 g
EQUIVALENTS OF INITIAL
OF NITRATE per AQUEOUS SOLUTION
Figure 10. Effect of various nltratea upon the partition coefficient of uranium with dlethyl ether. After V. Vdovenko and T. V. Kovaleva, reference 328. Condltlona. Temperatur~, ;5% ;‘%N;j’$ai~
of Initial. aqueous solutions; . g~oo
82
observed that the saltlng action of a mixture of nitrate O could be reasonably predicted by the followlng method: The logarithm of a for each salt at a given total nitrate molarlty II dlvlded by the total nitrate molarity. These individual quotlentB are then multiplied by the nitrate molarity of the reapectlve Baits. The sum of the resulting products ia then equal to the logarithm of the predicted partltlon coefficient. Hellman and Wolf-
have studied the salting action of
various nitrates in the presence of nltrlc acid and thorium nitrate.
Some of their results are listed In Table Ef.
From the data It may be observed that (1) thorium nitrate Is generally a less effective salting-out agent on a normallty basla than other metal nitrates and (2) the extraction of uranium becomes leas efficient aa the amount of extracted thorium becomes appreciable. The effect of several foreign anions on the extraction of uranyl nitrate by dlethyl ether Is given In figure 11~ and Table X.~ 26 Arsenate, molybdate,and vandate Ions also Interfere with the extraction of uranium.
The effect of
these ions may be offset by the addltlon of ferric nitrate to the solutlon.fi The partltlon of a large number of elements between various aqueous nftrate systems and cliethyl ether Is given in Table XI and illustrated In figures 12-14.
The Increased
distribution of heavy elements and fission product elements with increased nitric acid concentration should be noted.
For a
selective uranium extraction the nltrlc acid concentration should be minimal.
Hyd~
has recommended an aqueous
phase 0.5-1~ In nitric acid and 2.5~ in magnesium nitrate for the quantitative extraction of uranium by dlethyl ether. More selective extraction of uranyl nitrate may be made from a saturated ammonium nitrate-solution, 0.05-O.1~ In nltrlc acid.
The extraction can be made quantitative by repeated
contacts with ether. 83
(Textcnntinuesonpage 92.)
Table
IX.
Matrlbution
or
Uranium .2cdTnorium between Inethyl Ether d
201uti0nn Conwm
.%ltmg agent
Total nitrate no-
Canuonition
Lty
o. ~_ HN03
of initial + aaltlng
u extractd, $ HNO
3
Ll~3
NN4N03
3 5 7 7
23 52 62
2
10 36 74 81
3.5 $.5 7.5
~(N03)2
22
0
53 0.1
0.5 o.B
59
2.37 2.75 ~;$ 4.87 5.25 7.50 2.17 2.*
13 32 63 99 3 10
;::
3E
5.5
99
1,50
59
1.2
11
0.0 0.0
25 59 96 9
0.1 1.2
0.0
18.5
0.0 0.00 0.?,1
21.0
0.0 5.5
10
2.5
12
;:: 7.5 8.o 10.5 11.0
69 9 87
2.5
14 61 93
::; 6.0 6.5
m(No3)4
extmoted, %
2 66
07
~(N03)3
mm3 + lg lll(No3)4 + malting a8ealt
u ea-traoted,$ m
74
h(N03)3
mlutlm
o.~
25
M$03)2
m(No3)2
aaueaun
went
0.0
; 5.5 7 9 10 12
Ca(~3)2
Aqueoun
Varloun Amounts or Metal nitm3tm#
2.0 2.5 6:0 5.5 %
;:; 3.0 5.0 9.0 11.0
65 70 72
43
62 30 5 10 18 39
0.0 0.5 19 52 0.0 0.2 2.1
13 63
0.0
57
17.6
2.0
0.0 0.14 1!:!
g Afier N.N.Iiil~ andH. J.
336. 5 mlortho~~u @me or nppzmpriate 5,000 toS,000o/mor@33 traaar (52$mt~ meld)wre MWPlled to Varl~tlm orthetrncer from100tol@3,0~o/ih 5 tididnot :L%”;:”$%%i.ted.
Five ml of ether mmponltlon.
were
shaken
Wolf,
reference
10 mdmute ❑ with
04
-â&#x20AC;&#x201D; I00
90
NO:
eo
cl-
cgo:70
60
F-
50 so&
40
30
20
Po:-
r
10 0
1.0
0.5 MOLARITY
OF
INTERFERING
I.5
2.0 ION
Figure 11. The effect of various anions on the extraction of uranyl nitrate by di.ethyl ether. After T. R. Scott, reference 337. Conditions: Aqueous phase - varyhg amount of anion, 3N HN03, lg Fe(N03) ; aqueoua phase and organic phase shaken 1 minu~e at room tempera ?ure.
85
Table X.
The Effect B of VEW1OU6 ACida and Anlolle upon tha ~istribution Umnyl
Acidor salt present
Composition 4.2~
Nitrateto Diethyl ~ther.=
of aqueous phaee
. 4~0 (1W S/l)
Ca(N03)2
8~ NH4N0
6.8% NH#Oq
(640 g/17
(549 W’1) -
None
19.95
o. 6J15
HC1,lE
10.24
0.336
HC1,2g
6.34
0.182
‘N03’ 1~ KN03J 2~
43.56
1.162
71.2
1.g5
cH3c02H’ lY
15.7
0.662,0.616
a3c02H’2g
10.52
0.720,0.762
29.6
0.024
23.5
0.019
H#04,
o. O0391J
H.#q,
l!J
H2S04, 2tJ
Cctefflcient of
0. T164
0.613
0.609
H3P04,0. oo5a~ H3P04,lE
0.01
0.01
H3B34,2~
0.01
0.01
3.9
0.067
H3P04,lE HN03,2X
(NH; )2C204+ H20,0.7g/100ml
0.0847
H2C20Q. 250, 0.’7 .@Oo ml
0.0800
~ AfterFurman,NurIdy ad Morrlaon, reference 326. TheInlt Ialvolume ❑ of etherandaqueoua ❑olut ionwereequal. ROcmtemperature.
86
I00
10
1.0
0.1
0.01
i
0.001 I
01
I
1. I I 234567
INITIAL AQUEOUS Figure 12. ether.
I
I
I
I
I
I
I
I
I
8910111213
NITRIC ACID CONCENTRATION, ~
The extraction of varloua metal nitrate B by dlethyl
After R. &ck and E. Bock, reference 333. Condltlona: phase volumes. Temperature Initial aqueous Metal nitrate concentration O.lM 20 + 10C Saturated LiN03, Ca(N03)~, or Zn(Ng ); m;utlons O.lM 2 Ce IV) roo~ O.lm Au 111 200C O.m Sc 1] III Saturated LIN03 solutlonâ&#x20AC;&#x201C;
Th
87
equal
Al.
Q3, cml
a.ool
(0.
001
Am(VI)
#.ol O.lm
Sb(Y) An
o.W15’O .m-f’
0.04B*
rm. mol
tu.0005
Ba
0.014 0.073
Be Bi
O.ml
B
cd
Ca
.@.cca
0.M06
O*
0.0003 O.01*
mool‘@. mool o.om3 0.M05
Q3.
o.m7 0,033-0,39+
o.m2 0.00031
‘@. oml 0.K02 @.m.Jl a.omg
0.LW3
0.Ooml 0.0005
Ce( III)
27*
CS(IV)
Cr(III)
0.0001@.Cal
0.314
0.095
m
6.00C1a.mol O.M@. 0.M02
a
0.0M4 0.0003
Od
0.0001 O.mom
Cu. mol
<17 O.ow 0.%
@.ool o.m34
Au(III)
LI..C2(O.71)
H In Fe
@.oim4 a.om4 0.0W5 0.M05
La P-0 L1
0.003? @mm @.00002 o.oml
M
.o.mo82
< O,m%z 0,uz2 %2.3(36.5-50)
Oe
MO
@.ccco. @.wl
0.00-2
am
w ?2n(II) Nn(VII)
W.3(29.4)
a.mol
Cr(VI)
ml
0.021
o.m3
0.001 0.0013
o.ml
@.0001
o.m17
0.0001
0.M02 O.mol @3.oml <0.cccl
0.C05
a.mo2
0.0C02
0.M03
0.0002 a. owl
0.002 eJ. oo3 0.049 0.00+5
o.c03G.mol .a. oml a.ml*J**
e3.mm @.0001
@.oml 0.0003
m
Ni NP(~) NP(v) NP(~) P Fu(III) h(m) PI(VI) K Ha Ham ewthm se Rb Sn Sa h
0.M06
<o. mm m.0001 <o-mm
0,2 1.1
4.4 0.256
10.3 2.4
0.0005o,am2
0.002?
@. 00025 @JB325
<0.00025
1.5 ~.mol
0.03276 mKP335 ~.cQ31 <0.015** @.q5* a.015++ o.mo14 @.mog
0.013 0.144 0.001 0.025
se
.m. wol
o.ml
.
. ...
Sr
e.wol <0. oma <0. mm
Tl(I)
<o. ou&ao6&
S&
.@. ml <o. mo2 **, #.W05
<0.oml
G.0001 @. mol
@.oo5 o.ca3 0.528(0.531) 0.5 0.W?4 <<0.035
Tl(III)
m T1
0.0036
a.021*
U(VI) 0.69. 1.31* 165 2.09 o.mo6-o;ool” o.m&o. m8* V(IV) v(v) <o.mo5* 0.019+ 0.040* ●
1.30
?3.8
1.86(1.78)
1.85 2.3
0.07 O.cm a.ow9
Y
Owl a.Oax *.087 0.00110.011
<0. W05 .?3.0025 o.mo5 0,001+
m Sr ~
After FLIrmn,-y,
d
Morrison,
%.%%EY2R%%.IC?,
, h
326.
referenoe
tel~ 5g. or u 08 mm
gOnOti, 00 that app~
reoovered
to.pctograpl-d.a
In sena~ survey mtudlom, amdnst,on, Ag, ~, B, -, Bi, Ca, Cd, Co, Cr, G& Fe, Es, K; Ii, Ms, Nn, ?Ta, Ml, Pb. Sr. ’33, 2n, and 0.05 g. aaoh of In h Re waa pre8entalong with ~~1 mt~te M a tit~ agent, 00 g. rum 1C9 ml of amumnium fitrste d 100 g. per 1CM2 ml of oalcium titrate. (The lstter in equivalent to 4.23 ?4 if the malt 10 Conaiderati to b Ca[NOa), . 4HN. 4.%3 M if it in mc.nnldared to b7i cat-).). m-m na~d=&onoent~de .mrlptlon or the &&imant b&n & i% ferenae A table of the partition ooefflolentn .aoncentr&ed aoid pr 100 ml. tlon an of E21 given the said ooncer.tratlon EM &;h$ :~~:~%:ugm aoncentmtion 18 cwnd.dered to bs app ~?erlg a nltrla said oonaentration of the aqua~n molution aa O. were ~haken to ~ilibfium with an equel volume of ethsr a 20” C. ‘me uranium partition omffloienta are the mimm valuea detaded (Bee, slno, 0.1 g. of eaoh of the alementm:
326glvna thenltria.
5 mlof
f-Rare 9)●hrthm for indiviti ●
5 g.
ware present In amocmtm euoh that only limitSng value n could ba given elmtn bY tipeotrogrn~io UM83UI axaept fur Dy and (11.
Lar8e 3mmntm of olmenta were UA ?e lg , MO 0.3g per lrn ml. apectmgraptlic .
● ●
o.~2
* Limit set by lank of mensltivity ** Vmlenae ❑tnto not denlgnated.
● ☛☛☛
a
Is much
~ After
&ok
Value~ and &c,.
greqter
ud
! V 1-2.s,An Or Cr 16-mg, Ma or Ce nitrata 70-100s,
Aralynin of the
of swatro~phlo
for Mo prenent
Ilodc, referenoe
of a for 8M HKI
ether ptwme tie
FM a hetnropaly
bY IM=M
tent; a pro~bly
other than mnoh
tilar.
sold.
333,
❑olutiamn
have been aalaulatsd
mO,~VElrqm l%Frw”them. or interw u tad fran their data.
f,ram P-valuea
given by Eock
are .-”.1..38 given dlraotl,by Pack and WC,
Conce%ration of elaumnt oonoernsd in initial eolution: O. IN tith the axoeption of 0.94X, Sb, El 0.2N, W O. O&, H SE W& _, La o.m_, Pb Fe(III)0.4N for EIJ% , m o..&. – Elenen B were premmnt m the filtrate tith the followhg axaeptlorm: OE no @02, HFU4, A8 88 N@A1304, V an NR4V03,Cr an K2Cr207,MO m NH4-mlybdate. P am large.9t part Of tb ntimony van rne solution hydrolyzed strongly. f PMO1 Itated aa hydroxide h only tramm were dateated 2n the ether @baae. Cr fVI) extractd WB1l but an exaot value could not be determined ~caumn of raduotlon of t~ chmmlum. Xn(VII) was r.eduaed with the neparatlon of M@ from the ether 00 that pmmtloally m m wan axtmoted , Roam t~perature T@mperat-: 20” for the &Nzurat& NR4N&j and LIN03 Bolutiono. Por the ~ ~ aolutiona.
o.o?~.so0.2!
Al
(NH4 sb?)
~ After Kooi, rne
me
refermnae
valuea
given
336,
ti thin uolumn
are value m teken
from curves given
in thin raferenoe
.mlm, fimras 8 and 13). C.onmntzatlorm of the various elementm in the Snltlal aquecnm nelutlon: lTI, 22 mg U,3,3,10, 30 M S=3w ~r ml of UO@J3)2 . 6K2JC; Np and IBF a Of m(wa)4. 4F120; pi, tracer quan 2Itlem. No deteotnble difference =S obaerv~ Sn the p9rtition data for (...,
the ilrot three qu8ntitien of U llmted; a lower a (1 .7) nun obmmwti for the latter Concezltmtlon . -ihE t-m for the NP md Pu e%psrim.en~8 were kept nhort (15 sea to 3 m) to molutionm irdr.lml.odlnpmportionation to other oxidation atataa. inarname to two hours did not maim a difference in wan never lean thnn =he renulta.
5 tites. An
~ After Vdovenko,
reference
mO ehaking tti forU
344,
The initial aqueaum 18ger oontained, in addition to the acid nnd ealtlng agent, abat 0. 1~ of the nitrate examined. 2qual volum.eflof the aqueoua walutlon and diethyl ether ❑imuteo. After 12 hours equilibration a mampla of the o-o were ❑haken for ❑01utlon wan taken for
5
Emalyain .
208
0.01
I
I
I
I
I
1
i
I
1
I
1
I
1
I
1
o1234567e INITIAL
AQUEOUS
NITRIC
ACID
I
I
I
I
I
I
I
I
!
9
10
II
12
CONCENTRATION,
~
Figure 13. The extraction of aotlnlde nltratea by dlethyl ether. After J. Koof, reference 334. Condltlom: Tracer amount~ of Np 239 -d pU239 In aqueous BolutlonB were equilibrated with an equal volume of diethyl ether at 2Sâ&#x20AC;?C and room temperatum, respeotlvely. 330 mg of Th(N03)4 . 4H O per 15 ml of Inltlal aqueou6 solution waa equlllbra f ed with an equal volume of ether. tatea of neptunium ~ve been the ~ubJe~t Or .O%%%!!w%!$
90
10-’
a +Z
z o i=
I
Zr
, *-3
La
I 0-4
•1
I 2
I
10-5 o
INITIAL
I AQUEOUS
NITRIC
ACID
I
I
3
4
CONCENTRATION
~
Figure 14. Partition coefficients of fission producte between diethyl ether and aqueoug solution contalnl~ Ca(NO )2 and different initial acidltlefl. After V. Vdovenko, reference 34?. Conditions: Aqueous solutlon--requlred amounts of nitric acid and radioactive material added to 3.5~ solution of Ca(N03)2; Vofle, 1.
91
AgueouB ----- lJrSXIlummay be extracted -------- thloc~anate ----- -------8~6temB. 340,341 from aqueous thlocyanate aolutiona by dlethyl ether. Table XII llsta the partition coefficlenta of several elements from aqueoua solutlons of varloua thiocyemate concentratlom.~
A number of aubatancea notllated
in the
table give negligible diatributlona or diatrlbutlona of only a few percent under the condltlona teated: NH4, Sb(III), AS(III), As(V), Bi, Cd, CU(I), cr(III), Ge(~),
Ll, Hg(II),
Ta”bleXII. - Partition Coefficient’a of Varloua Elements between Dlethyl Ether and Aqueous Thlocyanate Solutlons.~ Composition of the Inltlal aqueous aolutlon HC1 M
t “c
0.5
20
o.2rJBec12
0.5
RT
O.uj COC12
0.5
O.lkJ GaCl
lg
NH4 SCN concentration 3g 5g
F
0.011
0.099
0.039
0.987
5.29
RT
0.037
1.39
2.9I3
0.5
RT
1.89
9.56
0.5
20
2.67
O.lM — InC13
0.5
RT
1.06
3.05
2.15
0.908
O.lM — FeCl 3 O.lPJMoOC13
0.5
RT
8.00
5.13
3.08
1.14
-0.5
RT
O.lg SCC13
0.5
RT
o.~(NH4)2snc16
0.5
RT
O.1~ TIC13
0.5
RT
O.lFJ TIC14
0.5
RT
0“1~ ‘02c12
0.5
RT
0.821
0.417
O.lM — VOC12
0.5
RT
0.176
0.095
O.1~ ZnC12
0.5
RT
3
HC1
140 0.145 144 1.43
12.7
31.1
3.04
59.4
36.@ 8.06
3.95
5.25
11.9
152
34.9
950
0 .2&
> “1OOO 3.94
> 1000 3.22 -0.15
23.7
37.8
~ After R. Bock, reference 341.
Equal phase volumes equilibrated at room temperature.
92
0.160
0.072 0.022
18.3
12.9
Nl, Pd(II).
Figure 15 rep,r~sents the change in ~
thlocyanate corkcentratlon for aqueous mlutlona acldltie *
~lYBIS
of
the
ammon~wn,
with
of different
uranium, thiocyanate
concentration of the ether phase Indlcatea that uranim
is
extracted as UOz~SCN)a~ A3ueouB fluoride s~stems. . -------------------- Uranium
is poorly extracted
by diethyl ether from aqueous fluorlde aolutilons. ~
Table
XIII llBtis the parbltlon coefficients of a number of elements from aqueouB solutilona of various hydrofluorlc acid concentratlona. Dlbut~l ether Aqueous nitrate - ------— -------s~stems. ------ The applicablllm ether as an extractantti
of dlbutyl
uranium has been investigated
extensively by workers In the Soviet Unloni~ 44,346-TJ+$) ~ibutyl ether offers several advantage
over diethyl ether.
It is less soluble in water, less volatile, and”has a htgher flash point.
The dlstrlbutlon coefficient of uxanyl nitrate
is, however, less for dibutyl ethep than for dlethyl ether. The partltlon of uranium
between water ~d
1.~
represented in figu~
dlbutyl ether la
The distribution of u.ranyl
nitrate and nitric acid is plotted as a funotlon of aqueous 346 nitric acid concentration In figure 16.— Khorkhovina, and Agashkina M
Karpaoheva,
have studied the effect of
various salting-out agents on the distribution of uranyl nitrate.
The salting-out action was found to increaae with
increasing valence of the cation.
The partition .coefftclent
of-uranium from an aqueous solution initially 0.5~ UOa(NO,~)a, 4.5~ Ca(~O~)a, and O.z
HN03 into an organic phase 8sjZ (by
volume) dlbutyl ether and 15% carbon tetrachloride is 0.70; a~(VI)
Is 0.42.~
Zirconium, niobium, and ruthenium are
the main fiselon product elements extracted.and BanerJe~
have studied the extractionof
Heyn bismuth
nitrate by dibutyl ether.and several other solvents.
93
I.0
I
I
I
2
I
1
I
I
0.I
0.02
0
INITIAL
AQUEOUS
3 4 NH4SCN
5 6 CONCENTRATION,
Figure 15. The extraction of uranyl thlocyanate by dlethylâ&#x20AC;? ether at various Inltlal NH4SCN and HC1 concentrations. After R. Bock, reference 341. ConditlonB: Aqueou8 phase-- initially O.1~, UOaCla and NH4CNS and HC1 concentration Indicated. Equal phase volumes equilibrated at room temperature.
94
7 ~
Table XIII.- part~tlon CoefflclentB of Varioua KlementB between Aqueous HF Solutions and Dlethyl Ethe# HF concentration of the starting aqueous solution 1.o_m <0.0005 0.111
0.Q03 0.227
O.olg
o .040
0 .Oby
As(III)
0.432
0.530
0.605
As(V)
<0.001
0.017
0.048
0.121
0.157
Be
<0.0005
<0.0005
0.005
0.019
0.042
Cd
<0.0005
0.002
0.006
0.009
0.014
co
<0.002
<0.002
<0.002
0.005
0.017
CU(II)
<0.001
<0.001
<0.001
0.010
0.013
Ge (IV)
<0.002
<0.002
0.005
0.028
0.072
Mn(II) F@(II)
<0.0005
<0.0005
0.002
0.005
0.013
<0.0005
<0.0005
<0.0005
0.009
0.028
0.007
0.018
0.031
0.062
0.103
MO(W)
5ioIgm
10.O&F
15.O~F
Elemen#
20.o_m
<0.0005
<0.0005
<0.0005
0.oo~
0.007
m(v)
0.006
0.044
0.480
1.08
1.92
P(v)
<0.001
0.011
0.032
0.110
0.173
xi
Re(VII)
0.0005
0.121
1.58
1.78
Se (IV) Ta
0.0006
0.022
0.080
0.131
41.012
0.774
3.8o
3.82
3.84
Te(IV)
0.0001
0.020
0,071
0.237
0.298
0.020
0.029
0.052
Q.oo& <0.002
0.053=
0.055
Sn(II) 0.0062
Sn {IV) u(w)
<0.002
V(III)
<0.0005
v(v) m
0.005
0.011
0.03
0.10
0.13 0.093
<0.002
0.003
1.62 .0.148
<0.001 <0.001
0.004
0.017
0.056
<0.001
<0.001
0.002
0.009
0.004
0.005
0.005
0.012
0.030
Zr
g After ~ck and Herrmann, reference 342. Equal phase volumes e@libmted at 20.0 + 0.5”C. The concentration in the tiltlal aqueous Solution of the Ionic species of’the element listed In the table was O.1~ in each case with the ex-ptlon of Re(VII) which was O.O~_. Fluoride stock solutlona were prepared In the following memner: carbonates (cd, Co, Cu, Mn(II), Ni, m) oxides (sb(III), Ge(IV), w(”lI), ~(v), se(~), Ta(V , Te(m), V~III)) ~r~d~xldes or hydrated oxides (SN(IV), Zr 1 were dissolved inar excess of HF; AS203 was dissolved in a known volume of O.l~NaOH and the calculated amount of HF added to the solution; EeF2 and SnF2 were dissolved; K2HAs04, Na2HP04, ~e04,
amnonium vanadate, smnonlum molybdate, and Bodlum uranate
were dissolved In HI’. 91.2gHF Q5.4~m ~ 10.4 gHF 95
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t
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10
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12
13,
14
15
NITRIC ACID
CONCENTRATION,
I 16
M
Figure 16. Partltlon of uranyl nitrate and nltrlo said between dlbutyl ether and aqueoua solution. After V. Vdovenko, A. Llpovskll, M. Kuzlna, reference 346. Condltlona: Equal haae volumes equilibrated at room temperature for both U02 7NO )2 and HNO extractions. points co~~spondlng t~ an acid eonten~~nn~~~q~~%~ aolutlon of greater than 13.4M were obtained by the extraction of previously acldif~ed dibutyl ether with concentrated nitric acid. For uranyl nltmte, points greater than 12.OM HN03 were similarly obtained. The uranium concentra~lon wafl78 mg@.
Dibutyl “Cellosolve” (Dfbuto~onoethyleneglyool Agueoua nitrate ~tems. - -------------------- A number of
)
cellosolve
derivatives have been Investigated for the extraction of uranium (T’ableVIII). extractant.~
Diethyl
celloeolve
1s an excellent
Unfortunately Its solubllity In water is
large (21X by weight at 20”C).
Dibutyl
cellosolve
soluble In water (0.2~ by weight at 20”C).
is less
However, It does
not extraot uranium as well as diethyl ether, either from water
96
solution (figure =)
or rrom aqueoue aluminum nitrate
aolut.ion (figure -). into dibutyl
The partition coer’rictent.Or uranium
cellosolve
from nearly saturated eolutionu of
ammonium, calcium, or rerric nitrate 18 1, 50, and 20, respectively.=
Dibutyl “Carbitol” (Dibutoxydiethylenegly col) A@eoue nitrate e@ems. - -----------------..- DibuW ueed in the reoovem
carbitol
(~tex)
of irradiated fuel material.=
iE
AeI a
solvent, it haa”been subject to considerable study.~ The partition of umnium it3given in figure 2.
between water solution and solvent
176,185,321
The partition Or uranium
between nitrio acid eolution and dibutgl illuet.mted in figure ly.~
carbitol
is
For aqueous solutionE in t~e
range of acid concentration, the partition coei’ficient IB observed to lnoreaEe with Increaaed uranyl nitrate concentration.
The partition coerricient of nitric acid is plotted
ae a function of acid concentration in figure 18.33 In figures19
and 20, the p=tition
4,753,35 4
coefficients of uranium
and Beveral other heavy elements are plotted against nitric acid concentration.
The initial acid concentmtion
aqueous phaBe is plotted h
figure 19.fi
oi’the
The equilibrium
acid concentration of the aqueous phase is given in fi&re 20.fi
Best, et hl~have
obeerved that the atee&ess
of
the extraction ourves (figure 20) is compatible with the romatlon
of the species HM02(N03)3 end H#(N03)6
in the
organic phase rather than suet M02(N03)2 and M(N03)4. curves given in
rigums
19 ad
20are
The
in general agreement
considering the difference In acid concentration plotted. There is a large discrepancy between NP(IV) data.
The
ability to maintain neptunium in the pentavalent state during extraction may be eub~ect to quemtion. fiueion product
elements ie given in 97
..
The xrtition
rig
of some
21 ror various
I.0
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Figure 17. Dlstrlbutlon of uranyl nitrate between dlbutyl carbltol and nltrlc acid Bolutlon. Adapted from C. A. KrauB, reference 353. Condltlons: Approximately equal volumes of organic and aqueous phase, Inltlally at the uranium and nitric acid concentrations Indicated, equilibrated at about 270C.
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8
I 9
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INITIAL AQUEOUS
NITRIC ACID
CONCENTRATION,
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Figure 18. Distribution of nltrlc acid between dlbutyl carbltol and aqueous solution. O, After C. A. Kraus, reference 353. ❑ , After J. Kooi, r fer nce 334. A, After D. G. Tuck reference 354. Condltlons: Equaljz~,z5$ or approximately equa135~ volume portl ps or sol%’ ent and aqueous solutlon equilibrated at -zYoc,z53 Yjoc,zZ and-zloC.z5h
I00 ~
1’
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d
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10 ~
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INITIAL Fl~re
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1
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19.
The extraotlon of actinlde nltrate6 by dlbutyl carbltol. After J. Kool, reference .334. Condltlone: Tracer amounts of Np239 or Pu23g, 330 mg of Th(N03)4 4H20 per 15 ml, or 300 mg of U02(NQ3)2 (hexahydrate) Per 15 ml Ln aqueouf3 nltrlc acid aolutlon equilibrated with an equal volume of dlbutyl carbltol at 25°C or room temperature. The oxldatl~~ states of neptunium have been the aubJeot Of some queOtlon.A
99
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Figure 20. The dlEtrlbutlon of actlnide elements between dlbutyl carbitol and aqueoua 8olutlon ea a f’unction of equilibrium aqueoue nltrlc add
concentration.
After G. Best, E. Hesfoti, and H. MoKay, reference 345. Condltlona: Tracer
oonoentratlons (-10-~)
100
of aotinlde. Temperature, 25”c.
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Figure 21. The partition of tracer amounts of yttrium, cerlum, and zirconium between dlbutyl carbltol and aqueous solution aa a function of aqueouB nitric acid concentration. After H. McKay, K. Alcock, and D. Scarglll, reference 355.
101
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EQUIVALENTS OF METAL NITRATE per 1000 cc OF WATER Figure 22. The effect of aaltlng-out agentB on the extraction of uranium by dlbutyl carbltol. eCu(N03)2, rnCa(N03)2, AZn(N03)2, 0A1(N03)3, ❑Fe(NO ) , &La(N03) After E. Evers and C. Kraus, reference 332. C!on2i?ions: Uran ;“ um concentration 2-6 g/loo cc Temperature, 2T°C; Vo/Va = 1. c~n~~~~~3. Af’$er D. Lee, ~? %%&d, G. Clewett, reference 3s8. : Trace amounts of uranium. Temperature, 2i’°C;Vo/Va, varied. aqueous nltrlc acid coneentratXons.~ iron Lnto dlbu~l acidity.=
carbitol
The dlstrlbutlcm of
1s increa8ed by an increase in
Chloride ton promotes the extraction of iron.
Boron .ia extracted by bubex, especially In the presence of copper nitrate as salting+ut
agent. ~
Vanadium and molyb-
denum are extraoted to several per cent.=
The extinction
of cadmium- chronium, nickel and titardum is small.=
102
The effect of Baltlng-out agentB on the dlOtrlbutlon of uranium into dibutyl -s
carbltol
haa been ButdIed.~’
ome of the results are presented In figure 22. A~ueous - -------chlorlde ---------~stems. ----.-
Uranium (IV) and (VI) and
thorlum are poorly extracted by dibutyl
carbitol
aqueouB aolutiona 2-6M in hydrochloric a.cid.~
from The extrac-
tion of protactinium 16 increased aa the acid concentmtion is increaBed. hyd~chloric than ~
From &_ HC1, apa is 10.
The extraction of
acid is negligible from aqueous aolutlonO leaB
in hydrochloric .acld. A third phase is formed upon
equilibration with 7.~_ HC1. large amount of the acid.
The third pha8e containB a
One phase resultB upon equilibra-
tion with 8.5hl.HCl. Pentaether (DibutoWtetraethyleneglycol) A~ueous nitrate - --------------s~etema. ------ References 33z and 360 summerize much of the data pertinent to the extraction of uranium by pentaether.
The distribution of uranyl nitrate between
solvent and water IB
given in figure 2A=
The parti-
tion coefficient of uranyl nitrate from various nitrate 360 media is plotted in figure Z?s.—
The distribution of
nitric acid as a function of aqueous acid concentration is also shown in figure Z’3.— 361
The effect of salting-out agents
on the partition of uranium is illustrated in figure 24.= Table X~
lists the partition coefficients of a number of
elements other than uranium between pentaether and various aqueous media.—362
Uranium is extracted by pentaether from
aqueous solutions containing amnonium nitrate and/or nitric acid in the presence of sulfate, phosphate, or silicate ions.& Phosphate ion, in large quantity, and soluble silicate ions are extracted by the solvent.@
Fluoride ion, in signifi-
cant quantity, interferes with uranyl nitrate,extraction. This effect may be overcome by completing the fluoride ion * with calcium or aluminum nitrate. 103
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CONCENTRATION,
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Figure 23. The partition coefficients of uranyl nitrate and nitric : l.Og. acid between pentaether and aqueouB solution. ~U02(N03)2 , diluted to 50 ml with acid of dedred minute with an equal volume of pentaether. :2::;t:;0%ds&kF? : 1.0 g. U308 dissolved In 10 ml of HN03 of gU02 N03)2 + NH4N0 desired Otrength af 2 er addltlon of 5 g. NH4N03j shaken with an equal volume of pentaether for 1 minute at room temperature. Adapted from oHNo : D. Musser, D. Krause, and R. Smellle, Jr., reference 360. equal volumes of nitric acid solutlon and pentaether equilibrate i for 1 hour at 250c. After C. Stover, Jr. and H. Crandall, reference 361. Cyclic etherO. A number of cyclic .ethere have been investigated as extractants for uraniun. the ~rane
Those sol~ent~ t~t
nucleus have been found to give good extmctlonB
of uranyl nitrate from aqueous solutlona. hydrocubor
contain
SolventB Or the
subatltuted tetrehydroftmane -e
found to be especially good.=
have been
The extraction of uranium
and thorium by four cycllo ethers LB Illustrated in figure 364 25 aa a funatlon of acid concentration In the aqueous phase.â&#x20AC;&#x201D;
104
..
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100
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EQUIVALENTS
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1 II
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12
W
13
I 14
Is’
1000cc
OF
WATER
1
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Figure 24. Effect of salting-out agents on the extraction of uranium ANaNO , vNH4N03, HCa(N03)2J 0A1(N03)3, gFe(N03)3. by pentaether. After E. Evers and C. h aug, reference 332. Condltlona: Uranium concentration, 2-6 g\100 cc of phaae. Temperature, 270C or room temperature. From figure 25+i, It oan be Been that uranyl nltmte
Is ex-
tracted more efficiently by the various aolventa than 3.s uranyl perchlorate.
Better separation of uranium and
thorium iB also achieved from nltmate aolutlon rather than perchlorate.
ESTERS Information 18 leas complete or leBB readily available for the extraction of uranium by eeterB than by etherB. The dlOtrlbution of uranyl nitrate between Ieo-amyl acetate and water IB repret3ented in f@ure~.— Karpacheva, et al.~have
185
found the extraction capacity
of butyl acetate to be Intermediate between dlethyl ether and dlbutyl ether.
Iiydeand Wolf,-
in addltlon to their
105 ,,
Table XIV.
Partltlon UoefflclentB of Elements between Eenta-ether and Various $kqueoua Medl& Aqueous solutlo~
Concentration h aqueoua phaae before extraction (w\25 ~)
râ&#x20AC;&#x2122;Jltrate
Nitrate + Chloride
Sulfate
Al
500
0.003
0.003
0.000
139 !1
362
0.02
7 501
0.35
Element
cd II
500
II
10
II
.521
II
500
n
10.4
cl n
4$36 494
II
10.3
II
9.9 500
Cr(III) n
0.026 0.053
0.01 0.004 -- c
0.011
--c
0.0001
0.00
0.020 0.026 0.02 0.025 0.03 0.003
0.004
0.0001
0.013
0.0004
0.002
0.00013
0.009
0.0065
10
0.0023
co n
555 500
0.007
It
11
0.012
n
10
ti(II) II
500
0.026
0.024
0.000
10
0.017
0.018
0.000
Fe(III) II
515
0.031
10.3
II
10.0
Pb
500
II
10
Mn(Ir) n
0.002
0.035 0.046 0.017
--0
0.007
0.005
500
0.0011
0.00006
10
0.0014
0.00075
I-@(II) 11
497 127
11
10 500
Mo(VI) 11
0.003 1.2
500
II
10
0.003
0.003
0.024
10.5
Ca
Sulfate + Chloride
0.015
0.21 0.036
0.19 0.41 0.028 0.10
106
0.176
0.23
0.10
0.001 0.015
0.03 0.001
Table XIT. - Continued Concentration In aqueoua phase before extraotiion (u\25 fi)
Element
0.0032
0.00064
500
0.00005
0.00001
10
0.00024
0.00
.500
0.09
0.005
10
0.32
0.005
SO~- (as(NH4)2S04) Il. Th II
500
Sn (IV) II
500
TI(IV) w v(v) 11
10
500
0.00
10
0.00 9.12
10
0.019
11
0.003
10 140
0.081
107
0.11
8.5 497
0.07
447
0.018
Zl?
8.9
0.00015
0.000
0.0006 0.00
0.035 0.0025
0.12 0.009 0.15 0.14
10 10
0.0001
0.22
14
II
0.0001 0.005
0.37
0.0024
II
11
11.5
87.5
II
Zn It
Sulfate + Chlorlde
0.0008
10 )
Sulfate
0.0001
10.3
11
Nitrate + Chlo~lde
0.0018
500
II
Ag II
Nitrate
516
Ni II
P(P~11
Aqueous t301utlo&
0.022 0.040
-- c 0.000 0.013
& Adapted from ‘- ‘“ Jones, c-4.360.3(1945). Equal volume portlona of aqueous aolutlon and pentaether. ~ Nitrate : 314 saturated ammonium nitrate Bolutlon. Sulfate : saturated ammonium sulfate Oolutlonm Chlorlde: chloride added aB ammonium chloride equivalent to the metal preeent. ~ Preclpltatea of Insoluble eulfate obtained In ammonium sulfate layer.
107
10
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F
—
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---
HGE04
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Figure 25, The effect of initial nltrlc and perchlorlc acid concentration on the extraction of uranyl salts (Fig. 25-A) and thorium salts (Fig. 25-B) by tetrahydrosylvane (THS), tetrahydropyrane (THP), 2ethyltetrahydrofura.ne (ETHF), and 2,5-dlmethyltetrahydrofur~n~~~) . After M. Branlca and E. Eons, reference 364. Condltlons: concentration, 2 x 10-3M. Thorium concentration, tracer UX1. Tempera+ o.2oc. vo/v:, 1. ture, 25 — 108
general Ourvey work (Table VIII), have studied the extraction of thorium and uranlum by ethyl acetate, n-propyl acetate, and Iao-propyl acetate aa a function of the nitrate concentration of the aqueouo phaae. observation of the latter grou~
316
It waa the
that the extraction of
uranium tends to decrease with Increasing molecular weight of the ester.
Therefore, only acetatee and proplonateg
need to be considered aerlou81y. extraction wae obeemed
Increased protactlnum
with increasing length of the It was further observed
alcohol portion of the e~ter.~
that hydrolysla of the ester tends to lncrea6e the extraction of both thorium and uranium.~
It was not dete@ned
whether
the addition of alcohol or orgemic acid cauaea the lncreaaed extraction.
Ethyl acetate AgueouB nitrate e~atems. - -------------------- The dlstrlbutlon of uranyl nitrate between ethyl acetate and water haO been e.tudledby 164 deKeyser, Cyprea, and Hermann.—
The partition coefficient
was found to vary from 0.17 at 227 U02(N03)2
“ 6H20 In the
aqueoua phase to 0.78 at 43$ aqueouO concentration.
In
laboratory practice, uranium Is extracted by the ~olvent from aqueous nitrate media.
The followlng conditions have
been UBed by varlouB groupO to extract uranium:
Grlmaldl and Levin~:365
9.5 g. of A1(N03)3 “ 9H20
are added to 5 ml of Bolutlon approximately 2.4? in HNO ~. 10 ml of ethyl acetkte are added and Bhaken at leaBt 30 seconds. Redden and ‘1’regonnln#:
Uranium precipitated In the
presence of aluminum (20 mg) with NH40H Is dissolved In 1 ml of HN03(1 to 1). 8 g. of Mg(N03)2 “ 6H20 is added and the volume ad~usted to 10 ml with water. 5 ml of ethyl acetate are added and vlgorouely 6haken for 2 minutes. (Used with 20-400mg samples of U3°8.) 109
Nietzel and DeSeaa_:
Approximately 15 ml of sat-
urated aluminum nitrate solution are added to 3 ml or less of sample containing 0.30 to 15 g. of U308 per liter.
20 ml of ethyl acetate are added and
shaken for 1 minute. Guest and Zimmerma@:
To 5ml
of mmple
containing
5% concentrated HN03 by volume, 6.5 ml of hot alumlnum nitrate solutlo~havlng are added.
a boiling point of 130”C. ,
The resulting solution is cooled, 20 ml
of ethyl acetate are added, and the mixture shaken for 45 to 60 seconds. Steele and Taverne~:
Approximately 5 ml of aqueous
solution are saturated with aluminum nitrate.
The
resulting solution is shaken with 10 ml of ethyl acetate for 1-2 minutes. In the procedure of Rodden and Tregonning, ~ trate is used instead of magnesium nitmte is to be made in the presence of phosphate. Ni2tiel_
aluminum niif extraction DeSesa smd
found that 1 molar concentmtions
of phos-
phate, sulfate, or carbonate ion could be tolerated with no ill effect on uranium extraction.
Small amounts of
sodium phosphate have been used to suppress the extraction of thorium without affecting the extraction of uranium. X28 Steele and Taverne&
report the extraction of appreciable
amounts of thorium and zirconium and small amounts of vanadium, molybdenum, and platinum by ethyl acetate. Grimaldi and Levine, = and DeSesa~
Guest and Zimmerman, —369 and Nietzel
have investigated the effect of a number
of elements on the recovery and/or determination of uranium according to their respective procedures. DeSes=
Nietzel’and
found vanadium, present in 100 mg amounts, was
precipitated and uranium was occluded in the precipitatate. Titafium was observed to partially extract.
This was pre-
vented by precipitation of titanium with p-hydro~phenylarsonic acid before extraction.
110
Aqueous thioc~anate ------- ------------~Btems. ------ Vano8al~
hae described a
procedure In which uranium la extracted by ethyl acetatie from an aqueouB phaBe containing an exceai3 of ammonium thiocyanate. Dizdar and Obrenovi~
have also investigated the extraction
of the uranyl-thiocyanate
complex by ethyl acetate.
IU3TONES Methyl ethyl ketone. A~ueous nitrate a~Btems. - -------------------- The distribution of uranyl nitrate between methyl ethyl ketone and water and between methyl ethyl ketone and saturated amnonium nitrate solution 10 given in f’igure 4-B.=
196 reportO a uranium Palei—
partition coefficient of approximately 25 between methyl ethyl ketone and an aqueous solution of 607 NH4N03 and Methyl ethyl ketone is not ae selective as 3“ diethyl ether.= Homogeneous solutions are fomned bely HNo
tween the ketone and .mequd. WdunE of saturated ferric or cupric nitrate at 20°C. M Miscellaneous agueous ------------- --------s~stems. ------ The partition coefficient of uranium between methyl ethyl ketone and an aqueous 60% NH4N03, 3% NH4SCN solution is about 2000.~
Iron Is
extracted. Mllner and Wo ~report
the separation of”tantalum
and niobium from uranium by extracting the fluorides of the former elements with methyl ethyl ketone.
Hexone (Methyl iso-butyl ketone). Aqueous nitrate s~stems. - ----------------- -between
The partition of uranyl nitmte
hexone and water is represented in figure q.~
The partition coefficients of uranium, nitric acid, and several other actinlde elements are plotted as a function of aqueous nitric acsd concentration in figure 26.=
The
effect of several salting-out agents on the partition coeffi111
10
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Figure 26. The extraction of’nitric ac~d and actlnlde nitrates, ll?h, u, NP,and Pu, by methyl Isobutyl ketone (hexone). After J. Kool, referenae 334. Condltlone:
239 or Fu239, Tracer amounts of Np 30mg Of Th(NO )4 “ 4H20 per 15 ml, or 300 w of U02(IJ0372 (hex@drate? per 15 ml In nltrlc acid solutlon ormitrlc acid alone equilibrated with an equal volume of hexone at 25°C or room temperature. The oxidation at tea of neptunium have been the mb~ect of some question.= t
112
clent of’uranium Is given In figure. 27.= co-worker~
have obBemed
Vdovenko and
an lncrea8e In the partltlon
coefficients of cesium, calcium, strontium, and lanthanum when the uranyl nltra~e concentration In the lnltlal aqueous solution Is Increased.
This has been related to
the extraction of the elements as metal uranyl trinitrate salts.
The partltlon coefficient of uranium from a h@hly
Oalted aqueoua solutlon Is decreased by an Increase In Krau>
uranium concentration.
observed \
to decreaee
from 153 to 78.3 as the Initial uranium concentration was Increased from ,5 to 100 grams In an aqueous solution containing 580 grams of alumlnum nitrate.
Jenkins and McKayfi
found au to decrease from 1.58 to 1.28 as the initial uranium concentration was Increased from 144 to 348 grams per llter in an aqueous solutlon 8~ in NH4N03 and 0.3~ in HN03.
In
the l%tter case, commercial hexone adjusted to 0.15~ HN03 waO used aB the extractant.
Figure 28 represents “the ex-
traction of uranium by hexone from aqueous solutions containing various amounts of nitric acid and calcium or sodium nltrate.—375 The distribution of U(VI), Pu(VI), Fu(IV), Th, La, Ca, Na, and HNO
by hexone from aqueous solutions containing nltrlc 3 acid and calclum nitrate has been Investigated by Rydberg and
Bernstr~m.~ of uranlun@
Hyde and co-workers have atudled the extraction and tho~l~
by hexone as a function of
the total titrate concentration of the aqueous phase.
Dlstrl-
butlon curves (a or P versus nitric acid or total nitrate concentration of the aqueous phase) are presented for the .varlous elements in the different papers. aluminum
The effect of
nitrate concentration on the extraction of fission
prtiuct gamma-activity In general and zirconium-niobium, cerlum, and ruthenium In particular is shown in figure pg.=
Increased extraction Is effected by an Increase
In salting-out agent.
An increase in fitrlc acid concentra113
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1213 CONCENTRATION,
Jkl
l?lgure 27. The effect of varloua saltlng-out agents on the extraction caNaN03, â?&#x2018;Ca(NO )2, ACO(N03)2, A of uranium by hexone. V Mg(NO )2, e13e(N0 )2, OA1( ?? ~ j. After W. H. Ea ? dwln, reference 319. Condl 2 ions: Equa ? volumes of pure hexone used to extract aaueoua containing 30 g U711ter.
114
10
1.0
,0-1
F
I
I I
o
NITRATE
I
~
4 3 5 ~, OF SALTING-OUT
AGENT
I
z
CONCENTRATION,
I
6
Figure 28. The partltlon coefficient of uranium as a flmctlon of the nitrate concentration of the salting-out agents, Ca(NO~]2 and NaNO ~, for an Inltlal concentration in the aqueous phase of 100 g/1 of uranium and I,Z?,3, or 1~ HN03. After A. Cacclarl, R. DeLeone, C. Flzzottl, and M. Gabaglio, reference 375.
tlon also causes an increased extraction of flsslon products (figure 29).= The extraction of uranium by hexone is facilitated by the presence of subBtltuted ammonium nitrates which are sufficiently Eoluble in the organic solvent.
A number of
these salts and their effect on the extraction of ursmlum are listed In Table XV.=
Tri-n-butylamlne,
2-hexyl pyridlne,
and dlbenzoyl methane increase the extraction of flsslon products.â&#x20AC;&#x201D;378
Maeck, et al.=
have investigated the extrac-
tion of uranium by hexone from an aqueous solutlon containing alunlnum nftrate and tetrapro~lanimonlum nitrate. The extraction conditions adapted as a result of the
115
10
Lo
0.1
0.01
J
0.001
“-N’
~/
0.0001 0
I I ALUr
INUM
/o-’MBa’a
I
I
I
I
1
2
3
4
5
6
NITRATE
CONCENTRATION,
~
Figure 29. The effect or salting-out agent, A1(N03) , on the extraction of uranium and flesion products by hexone f 2 om aqueoug solution at varloua nltrlc acid concentratlonB. After F. R. Bruqe, reference 378. Condltlons: The result6 on uranlm and gross flsslon product activity were obtained using QP. AI.(N03) as sdltlng-out agent and pretreated hexone as solvent. ~n irradiated uranium slug, cooled 144 days am”dlsBolved in HNO ~, was used as,actlvlty source. Extractions were made at 30 C fmm am aqueous phase oxidized 1 homwlth O.1~ Na2Cr 07 at this temperature . The nitric acid Is the sum of zhat In the aqueous and organic phases, expreBsed as moles of nitric acid per liter of aqueous phase. Ruthenium extractlon:aqueous phase--O.lM K2Cr207, 0.2M A1(N03)3. ’03 ‘ Cerlum extractlon:aqueous phase--O.O25M Na Cr O 2 27s 0“5~ Al(N03)3. ’03 ‘ Zirconium-niobium extraction :aqueous phase--O.l~ K Cr O 2 “27’ 0.25~HN03~ 8 g U per liter.
116
Table XV.
Effect of substituted ArmnoniumNltmtes ~xtracticm
of
Cation, R
(RN03) on the
Uranyl Nitrate by H.exone.~ Total RNO 3 ,concentration
%
(mol/1 x 103) o
None (c4H9)3~
cll%5~
s
:
2.62
2.1 4.2 11.0 21.0
6.2 10.7 32.4 68
2.5 5.0 10.0 20.0
6.0 .4 z ;3.5
2.0
5.4
5.0 10.0
13.4 26.7
20.0
57
C12H24N2H
2.1 10.5
(C4H9)4N
10.0
97 84
10.0 c#+.Nâ&#x20AC;&#x2122;H =
10.0
2.8
(C2H5)3NH
10.0
4.0
(CH2CH20H)4N
10*O
2.67
~ After Kaplan, Hildebrandt, and Ader, reference 78. Condit.ionB: equal volumeB of hexone and of an aqueouB oolution. 8~ in NH4N03, b.4~ in HN03, and about 0.021-Jin uranyl nltra%e. ~ di-2-ethylhexylammonium
~ methyl iBobutyl ketazinium ~ 2-methylpyridinium Investigation were 4.0 ml of 2.8~ alumiiumn nitrate, 1~ acid-deficient,
containing O.l$%(weight/volume) tetra-
propylammonium nitrate; 2.0 ml hexone; and a eample 8ize of 0.5 ml (-2 mg of uranium).
Theee conditions provide
a good separation of uranium from many ions.
The separation
from zirconium-niobium
The recovery
16 particularly good. 117
of uranium Is excellent even In the presence of foreign anions (10 to 1 mole ratio of anion to uranium). anions tested, tungstate ion
Of those
Interferes most seriously
(only 64.z8~ uranium extracted).
Chlorlde, sulfate, phos-
phate, acetate, oxalate, etc., In the amounts teated, exhlblt no appreciable Interference In the extraction of uranium. Chloride does promote the extraction of those Ions which form anionic chloride complexes, eg. gold (III).
Certain
other anions enhance the extraction of fission products, eg. bichromate and thiosulfate Increase cerlum extraction.
Aqueous thloc~anate - ---------- -------s~stems. ------ Uranium (~) IS extracted ~ea~ by hexone from aqueous thlocyanate solution. ~ hae Investigated the separation of uranium and thorium by this means.
Some of hls results
are given In Table XVT.
The
effect of sulfate ion (experimental conditions B) is to hinder the extraction of both thorium and uranium.
The
effect, however, is greater for thorium than for uranium. Consequently, greater separation of thorium and uranium can be made In the presence of the completing sulfate Ion. The extraction of protactinium from an aqueous solutlon 1.2M in NH4N03, 0.20~ In HNO~, about O.01~ in Th(NO~)2, 0.00g8~_ In Na2S04, and 0.501~ in KSCN by an equal volume of hexone was ~ 4.4$. too good.
Decontamination frcm fission products Is not Equlllbratlon of equal volumes of hexone and
an aqueous solution approximately O.Oqy in U02(N03)L, 0.504~ in Th(N03)4, 0.q8s~ in NapS04, and 1~ In HN03 resulted In a beta decontamination gamma decontamination
factor of about 6.6 and a soft
factor of about 1.5.
Zlrconlum was
found to be the principal flsslon product extracted.
Methylcyclohexanone Agueous nitrate - ------------- s~stems. - ------
This solvent has been studfed
118
Table XVI.
Separation of U(VI) from Th( IV) by Thlocyanate Systems.g
Expertiental conditions
KSM ~
U extracted
Th extracted
A
0.27
64.5
1.03-1.6
A
0.54
82
1.5-1.8
A
0.9â&#x20AC;&#x2122;7
89.5
2.1-3.1
A
1.62
A
0.32 + o.llM antipyr~ne
95 79
3.3
5.2-6.2
B
0.501
63
0.14*
B
0.25
35
0.015*
~ After W. H. Reas, reference 380. Experimental condltlon6: A: B:
*
0.16~ UO (N03)2, 0.81~ Th(N03)4, volume of aqueous phaae = :.2 ml, volume of hexone = 10 ml. 0.0974~U02(N03) , 0.252~ Th(N03)4, 0.2N HN033 0.224M Na2S04, volume o? aqueou, phase = 10 ml, volume of hexone = 10 ml. The thorium extraction was performed under Blightly different conditions In that NH NO was substituted 8 ) %acer was added for UOP(N03)P. An ionium (TIIPS to the eolutlon and the dl.atrlbutfon was measured by the determination of Ioniurn in each phase.
by workers in Czechoslovakia as a means of separating uranium from thorl~and
fleelonproducte.~
The extracta-
bility of uranium by met,hylcycloliexancine from sodium nltrilte solution (6-8~) Is considerably better than that of thorl~ 381 From nitric acid solution (8kQ),the extractability of uranium IB only two- to three-fold greater than that of thorium.~ Ammonium nitrate Is comparable to sodium nitrate as a ealtingout agent for uranlum.â&#x20AC;&#x201D;323 tham either.
Al~lnw
nitrate 1S more effeCtiVe
However, the order of saltlng-out agents In
cauBlng Increased flsslon product extractability Is Al > Na > NHu .
The best eeparatlon of uranium from f16elon producte
is achieved with ammonium nitrate aa the salting-out agent.=
Methylcyclohexanol
preBent In commercial methyl-
cyblohexanone suppresses the extraction of uranium and flsslon 119
products.
The Beparatlon factor between the two actlvltleB,
however, Is increaBed since the partition coefficient of 323 fiBa~on productB Is decreaBed more than that of uranium.â&#x20AC;&#x201D; The partition of uranium between methylcyclohexanone
and
water and methylcyclohexanone and 6~ ammonium nitrate solution Is given in figure +B.~
Other ketonlc solvents Hyde and Wolf-
have studied the extraction of uranium
and thorium by methyl n-amyl ketone and dllsopropyl ketone as a function of total nitrate concentration In the aqueous phase.
In both cases, uranium was better extracted than
thorium. (f57) mtil than 5~.
The extraction of thorium did not become appreciable the aqueous nibmte
~ncent~tlon
waa greater
Dlisopropyl ketone was found to bean
excellent
extractant of protactinium.~ Vesel$, lleranov~, and Malyâ&#x20AC;&#x2DC;~have
investigated the
extraction of uranium and fission products by several methylalkyl ketones: methylheayl, methylamyl, methlbutyl, and methylpropyl In addltlon to methyl isobutyl and methylcyclohexanone.
The partition coefflclentO of both uranium
and fission product activity we.R measured as a function of acid concentration in the range of -0.4 to 3F!nitric acid. In thla acidity range, flsslon product extractlonwa8 to be maximum In the O-ly nitric acid reg~on. coefflclent, aFp,
found
The partition
In this region was greatest with methyl-
propyl ketone (22 x 10-3 at 0.61M) and least with methylhexyl ketone (2.4 x 10-3 at 0.03~). region, app increased -
the acid-deficiency was decreased
(the solutlon was made more acidic). ~p
In the acid-deficient
was reached In the O-l~acid
After the maximum
region, the partition
coefficient was decreased and then Increased as the aqueous solutlon was made more acidic up to 3-4~.
120
The partition
coefficient of uranium, au, Increaaed aB the nitric acid concentration wae Increaaed over the entire range.
At 3g
nltrlc acid, au varied from about 0.7 for methylhexyl ketone to about 2 for methylpropyl ketone and 3 for methylcyclohe%anone. *
The greatest 6eparation, ~, of uranium
from fission products was found in the O.1~ acid deficient region (-O.1~).
For methylhexyl keton~ @ was found to be
>1500; for methylpro~l
keton~p
was about 400.
The extraction
coefficients of uranium were < 0.2 for methylhexyl â&#x20AC;&#x153;ketone and about 0.5 for methylpropyl ketone at this acid concentration. Alle~
has tested diisobutyl ketone, diisopropyl
ketone, and methylhexyl ketone as solvents for the purification of uranium from iron, copper, chromium, and nickel. Diiaobutyl ketone waB found most satisfactory under the conditions tested., Diisopropyl extracted some Iron and chromium.
Methylhexyl ketone extracted iron, chromium,
and copper. Uranium and thorium may be extraoted quantitatively from a nitrate medium by mesityl oxide.â&#x20AC;&#x201D;384
Under the concli-
tlons tested* zirconium is extracted to a large extent; vanadium and yttrium to a lesser extent; cerium only slightly.
ALCOHOLS Hyde and Wolfti
found alcohols to be only fair ex-
tractants of uranium and the extraction capacity to decrease rapidly with the length of the carbon chain. out by the work of Poston, et al.=
This is borne
who measured the ex-
traction coefficients of uranium and rutheniun as a function of aluminum nitrate concentration of the aqueous phase for *
Expertiental conditions: A salt of the elements tested was dissolved in 10 ml of HN03(15 + 85). Nineteen grams of aluminun nitrate crystals were added smd dissolved. The solution was shaken for 15 seconds with 20 ml of mesityl oxide. The extract was washed once with 20 ml of aluminum nitrate solution and analyzed.
121
hexone and several tertiary alcohol B: te~tiary en!yl alcohol, 2-methyl 2-pentmnol, 2-methyl 2-hexanol, 2-methyl 2-heptanol. Only tertiary amyl alcohol extracted uranium better &an hexone (0,5 - 1.5~Al(N03)3,
0.2_M03)
and all four alcoho16 Ruthenium was
extracted ru%henlum better than hexone.
extracted as well or nearly as well as uranium by the alcohol S . Dllsobutfloarblnol as uranium.= tracted.
extracts ruthenium nearly as well
Thorium and glrcotium-nbbium are poorly ex-
Protactinium Is extracted much more efficiently
than ll~lll?ll.
MISCELLANEOUS
SOLVENTS
Nltromethane has been reconsnended by Warne~ .extractant for uranium.
as an
It Is resistant to oxldatlon,
stable to high concentrations of nitric acid, and highly selective.
The dlstrlbutlon of uranyl nitrate between
nltromethane md
water and nltromethame and saturated anunon-
ium nitrate solution is given In figure 3-B. The extraction of thorium nitrate by nitromet~fl-om much less than that of uranium.
Color tests Indicate that
neither copper, cobalt, iron ~),nor extracted by the solvent.
aqueous solutlon is
chromium nitrate Is
With dlethyl ether, considerable
emounts of copper titrate and trace ,amounta of ferric nitrate are extracted.
Nitric acid enhances the extraction of uranyl
nitrate by nltromethanem concentration
However, above a critical acid
(-5N Initial acid concentration with equal
phase volumes at 20â&#x20AC;?C) only one liquid phase IB formed. ORQANOPHOSPHORUS COMFOUNIS. lar&
Within recent yeare, a
number of organopho~phorous compounds have been developed
and investigated as extractants for uranium. have been aubdlvided in the present -per aoidio organophosphorus oompunds. 122
These compounds
intO neutral and
NEUTRAL ORGANOPHOSPHORUS COMPOUNDS Solvents Included In thle category are trlalkylphoaphatea, (RO)3P+
O; dlalkyl alkylphosphonates,
dialkylphosphtnates,
(RO)R2P4
(RO),#lPa O; alkyl
O; and triallcylphosphine oxides
The abillty of the Bolvents to extraCt uranium Is RP+O. 3 In the order (RO)3p~O
< (R02)Rp4
o < (R0)R2P+
o <,R3P~,0.
This la also the order of lncreaBlng base etrengths of the phosphoryl axygen.—3W
In Table XVII, the four types of
compounds are compared as extractants of u~anlum
(VI),
plutonium (IV), thorium, flsslon products, and acida.~ It should be noted that although uranium 16 extracted almost quantitatively by tributylphosphine oxide (Table XVII), other elements are also highly extracted.
In fact, in spite! of
lower extraction coefficients, tributyl phosphate afford8 a better separation of uranium from thorium, plutonium
(IV),
and flflsion products under the oondltions listed in Table XVII than does tri?mtylphosphine oxide. Tables XICtiI=
and XIX=
list the distribution co-
efficients of uranium and Borneassociated elements for a number of neutral organophosphorus extractants.
Similar information
on other solvents may be found in papers by Burger, ~ and Kennedy,~
and In numerou6 ORNL re~rts.
been summarized by Blake, et al.~and
~O~n,
H~~y
The latter have et al~=
The mechanism of extraction by neutral organophosphorus 188 reagents appears to be similar to that of tributyl phospliate.-’ _
FrOm nitrate
Syotems,
the extraction of uraniumby
tributyl phosphate and triootylphosphine oxide is described fairly well by the equilibrium reaction Uog+ + 2N0 ~- + 2S = UO~(N03)2 (S)2, where S represents the solvent molecule.—3W
~traction
may
be made by tributyl phosphate from chloride solution. Stronger 123
Table XVII.
Comparison of the l?xtractiveCapacities of Various Types of OrganophoBphoru~ Compound&
IEX ractlon of
Extraatlon of U. Pu. and Fission Productfl~ -
Extraction of U02(N03)2 Nttrlc acid aoncentratlon
0.63 HNO
No added HN03 ?mTamTaext 1c ext Id ext 1d (%) (z) (%)
ext 1(
(%1 Tributyl
I
J
VI)
[%)
Iv) %)
3 Th ext’d (%)
G7?OS.E
k
0.01
0.01
j8
6.6
0.07
0.08
3.5
64
1,1: 0.05
0.13
37
54
0.72
1.0
18
14
94
20
1.9
7*9
9941 98
23
38
74
17
99.9 97.
37
64
999
77
98.7
56
4
96,5
8
17.4 0,7
55
97
6
99.4
11
~ibUt791@V38phinate
98.5
99.9
15
99.9
mibutyl phosphine oxide
99.7
99.9
39
99.9
Dibutyl butylpho8phonate
I
w [[f)”
11
phoBplUate N &
u“
Butyl
+
99.1 72
1 ~After
Higgins, Ealdwin, and Ruth, reference 387.
Experimental conditions: equal phase volumes equilibrated 30 minutes at 25 t 0.2”C; organic phase - 0.75 M phosphorus compound dissolved in CC14; aqueous phaae - O.1~ uranyl malt with or without”sa~tlng agent. b Aqueous phase O.1~ U02(N03)2 from dlscolving irradiated U slugs In W03 ~Aqueous
phase - o.l~Th(No3)p
- 6 monthE cooling.
Extractlo Qf U09S0 ~
Extraction of uJclp —-
H2S04 concenration
HC1 concentration
OM —
OM
2g
Extraction of aold~ $ extracted lM
clt- Tar- HNoz rlo taric
H@04 H3P04
HG1
tio
25
0
0
7
0
0
0
Aoe
u ext’d
u ext’d
u extld
u axtld
0.001
0.001
0.3
0.8
0.1
0.03
1
26
Butyl dibutylphosphlnate
16
48
40
92
49
20
20
27
2
3
0
Trlbutyl phoaphlne oxide
95
96.*
90
all precipitated
58
39
23
39
0
10
7
Trlbutyl phosphate Dlbutyl butylphosphonate . tv m
Oome ppt. formed
~ Aqueous phase - o.ly U02S04; acid ae indicated. s Three phases were present, two of which were largely aqueouO. ~ Aqueous phaee.
approximately lx acid.
Table XVIII.
Extraction of Aatlnides and Ztrccmlum by Phosphates and Phosphonates at 30°(!$
Solvent Th Trialkyl phosphat~ n-butyl Isobutyl n +amyl iso-ariwl n-hexyl n-octyl 2-ethylhexyl 2 -butyl 3-amyl 3-methyl-2-butyl 4-m3thW-2-amyl cyclohexyl . ~
Dialkyl alkylphosphonat~ dl-n-butyl n-butyl dl-n-butyl oyclohexyl cll-n-amyln-amyl dl-n-hexyl n-h~l dl-2-ethylhexyl 2-ethylhexyl
~After
Np(IV)~
2. 2.? :.; . 2:: 2.5 0.45 0.22 0.16 0.047 3.5
Pu(IV)~
Extractio Coefficl nt U(VI) Np(VI)~ F$.@@
16.1 11.8 15,6 17.8 15.6
15.6 15.9 19.3 18.9 20.0 15.7 23 20
Zr
0.22 ;:? ::: 4.5 3.9 5.7 4.6
0.12 0.14 0.14 0.14
24 22
24 17 3 22
%5 133 89
0.1 0.1 Ooogf? o.o’@
10.6
176
0.12
I
T. H. Slddall 111, references 388 and 389.
~Aqueous
phase oontalned O.OJPJferrous sulfamite.
~Aqueous
phase oontained 0.01hJNaN02.
~ Aqueous phase contained O.01# oeric amnonium Bulfate. ~ l.0~ trid.kyl phosphate in n-dodecane; extract.antswashed with 1~ N80H, water, and nitrio &iold_%eforeuse; aqueous pbs.et? 3,0JJHNO at equilibrium; traoer concentration of element. 3 ~ 1.09M phosphonate tn n-dodecane;d,quemus phase 0.81JHNO at equilibrium; traoer concentration 3 of e~ement. ~Eztrapolated
value.
extractants may extract uranium from sulfate and phosphate 8olutlon6, eapeolally if a emall amount of nitrate la added to the solution.
Trlbutyl phosphate (TBP) Agueous nitrate s~steme. - --------------------
Inveatigationa on the ex-
traction of metal nitrates by TBP Indicate the cations are extracted as single, well-defined species: M(N03)3(~p)3, 168,187,311,392,393 This M(N03)4(~p)2, -d M02(N03)2(~p)2. dlffere from the extraction of ethers, este~s, and other oxygen-containing a whole series
solvent~, consid-ed
previously, in which
of complexes containing varying numbers of
nitrate, solvate, and water molecules Is extracted.
The
stability of the TBP-solvate molecules lncrease6 in the orde s H20(mP)
< Pu(N03)3(T13P)3 < Pa(N03)5(TBP)3 <~03(T13p),
HN03(TBp)(H#)
< Th(N03)4(~p)2
‘(N03)4(~p)*
< ‘0~(No3)2(~pl*.
< pU02(NC13)2(~p)2 <
The unexpectedly lerge eXCrac&lon of nltrti acid, thorium, and zirconium at very high acid concentrations Indicates higher complexes may be extraoted.—311 The distribution of uranyl nitrate between-TBP and water 394 is represented in figure 30.—
The extraction coefficient
of uranium Is plotted as a function of acid concentration for various concentrations of TBP In figure 31.~ effects of (1) decreased ~
The observed
with Increased acid uoncentratlon
and (2) Increased au with increased TBP concentration, may be explained on the basia of free solvent concentration. First, as the acid concentration la increased, more nitric actd Is extracted resulting In leOs free solvent.
Second,
more free solvent is obviously available as a result of increasing the solvent concentration.
Since the partition
coefft.ci.entof uranium depends upon the second power of the free solvent concentration, au will decrease In the first case 127
Table
X~.
~traotive
Power
of Tributyl Phosphate, A1.kyl Phosphonates, Mphoaphonates, am!Phosphine Oxlc!e#.
Initial comentration of HN03,1J0.5
1
2
0.5 DiBtribUt,iOn
Solvent
u
1
2
I
0.5
1
2
~
0.5
Pu(rv)
0.68 1.42 ~B&
LZr-Nb
N’b
0.19 0.67 2.7: .64 4.5010.35 21.5c 5.46 11.15 14.9( .w58
.0040 ,015 .cool
o (i.45H110)2P~3
6.9521.1070.6c 1.53 7.43 16.9c .15
.22
(c6H130)2f\%
5.7210.45 b5.7C 3.51 11.65 18.9f .10
.C53 .13
21.30g.1
K131
22.1050.70@.o
(c4%30)\p0. (c#130)/ ~
CH3
L 05
.011
.014 .010 .0020 .017
.52
.34
.0050
.012 .021
3.25 10.95 17.1: .0078 .040 .12
.amo
.m%
5.71 13.65 19.4: .037 .14
.28
.0061
.019 .044
.33
.20
.ma%
.67
.55
.013
.014 .017
6.7314.65 34.3( 16.60 21.65 21.5( .3
,40
.54
,LD43
.aX3 .-
.015
.013 .0%7
.86
.40
.15
.24
.m56
.0053 .0062
.0038
.0041 .0051
7.5822.50 57.30 2.s3 7.67 14.8s .00!35.018 .11
.0021
.0089 .039
10.4522.20 74.70 2.58 8.65 ~6,75 .0039 .020 .10
<.cun6
4.47 17.35 25.1! .0s!0 .061 .30
0.03 o.c53 0.1! 1.84 1.34 1.7:1.31 L 42 13.4328.80 69.9c 3.80 11.60 19.6( .24 u.m 36.3 65.8
7.89 17.85 24.50 .80
4.w 13.05 44.20 2.*
(C4H90)2P~o C+-+-n
.86
27.6032.60 61.4c 23.25 24.15 21.7[ .97
17.4544.10 lol. o ‘o (c#50)2pkc%
2
00efflOi.9ntB
(C4H9@2P-&
(C4H90)3P0
1
.16 .47
7.58 14.65 .031 .cgl
.47
.086
.33
.0228 .0063
(i-C5H110)2PN - C3H7-n
9.4022.30 73.80 2.02 7.46 14.15
(c4H&)2PN:4H9
8.9824.00 65.30 2.82 9.46 17.50 .0034 .024 .097 c.001
.C028 .025
(C4~o)2p:C5HII
8.2625.75 11)3.52.45 8.91 17,65 .0032 .024 .11
.0035
.010 .032
.011
.022 .074
(i-C5~10)2:XC5H11
-
.013 .O%
13.6528.@3 58.4o 2.50 9.00 15.75 .012 .036 ,13
,0022
.0027 .0022
(i-C5H110)2P~: C5H11-1 o (i-c5Hllo)2{\C~H17
7.6821.10 30.95 2.18 7.69 13,05 .011 .031 ,13
.0017
.W24 .0031
9.6o11.50 85.4
.0012
.011 .029
(C4H90)2{&C6H5
2.45 6.34 21.10 0.47 1.91 6.00 .0034 .0084 .025 .W2
2.65 8.92 17.00 .016 .038 .13
.“0011,0012
(C41$O)2+$OCH3
1.13 3.09 7.79 0.28 1.16
4.24 .0-29 .075 .12
.0029
.0046 .0061
(c4H#)2;:c~~#5
1.31 3.11 8.86 0.34 1.50
5.03 .43
.C046
.0057 .0067
.42
.42
3.15 8.68 42,20 0.80 3.26 10.95 .031 .077 .062 .0050
.0060 .012
(C4H90)2+(CH3)C%; -0C4%
2.30 6.35 34.50 0.15 2.35
.0041 ,0058
(C4~0)*P~c~c~C0&4H9 o
2.14 5.57 16.46 0.79 ,2.38 6.24 .074 .12
.057 .0058
.0000 .0066
(c4~0)2p~
1.7312.55 17.26 2.71 6.72 19.24 .23
.29
.011
.011 .011
1.32 2.98 9.60 3.33 8.45 24.70 .41 .41 .42 (i-C5H110)2P\C% - P(OC5HII-I)Z o $ L880 1360 352 365 299 83.2 1.00 1.84 2.4s (c4q3Po
.032
.031 .031
(c@2~0~c~oC
c%
IJ$
- ‘~9°)2
o
(i-c4q3m
6.39 .021 .025 .043 .0031
.28
0
>
5.33 7.26 7.19 Ui% 21.85 22.55 .61
.55
.55
.64 ‘.95
.60
.47
4,40 2.15
reference 390. E AfterPetrov, ~., Organic we - 0.5Mphoephorue compound in CCli. Initial ~ ueousphase- 50 E/lU, 1 &l Pu(Iv), 1 o\lZr95+ N%95, 1 c/1Fib , nitrio=oidas indicated. Volumer tio (organic aqueous), 2. Time of shaking and of settling, 30 minutes. Temperature, 2!3” * 1°C, 1 - iao; c = Oyclo.
10
_
1
I
,
1
1 I 1 1
I
1
1
1
1 1 1 I
I
1
1
1
I
1 1 n m
1
1
1
1
I
I
u
r 1 ,
1
1
1
1
I
1 1 1 111
I
1.0
a
s : 1 : 0
2E
0.1
0.01 0.01
11
II Lo
0.I
MOLALITY
10
(aq)
Figure 30. The partition of uranyl nitrate between 10QZ â&#x20AC;&#x2DC;llBP and water at 25â&#x20AC;?c. After T. Hefily, J. Kennedy, Q. Walnd, referenae 394. and Increaae In the Eecond.
on ~
The effect of uranium concentration
Is given also as a function of nltrlc acid concentration
in figure 32.~
The deoreased extraction with increaaed
uranium concentration may again be interpreted In terme of the solvent available.
The partition coefflclenta of other
metal nltratea are alBo deareaeed, In general, by Increased uranium concentration.
More efflolent separation may there-
fore be achteved by Inareased uranium loading of tlae For small amountB of uraniqa
solvent.
high uranium concentration may
be attained In an organic phafle suitable for handling by 130
1000
i
I 00
10
1.0
E4
93â&#x20AC;&#x2122;%
TBP
D
58%
TBP
e
39%
TBP
o
19%
TBP
1
0.1
i
0.01
01
23456789 IN!TIAL
!01!
AQUEOUS NIT RIG CONCENTRATION, ~
!2
ACIO
Figure 31, The extraction of uranyl nttrate by various concentra tlonB of TBP in kerosene as a function of Initial aqueous acid concentration. After T. Sate, reference 395. Condltlons: Organic phase - volume $ TBP in kerosene as indicated. Aqueous phase - 5 g. uranyl nitrate per liter , nitric achl concentration Indicated. Temperature, 200C; Vofla, 1.
131
I00
I
1
1
1
I
1 I 1
I
I
1
I
1
!
I
1 .
I Ii
I
1
0.005 ~ 0.025 fq 0.05 fjg 0.01 ~
I
m B m 1-
I
I 1 1 1.
e o .+ 0 :
0.2 M
: c
10
s 0.3 ~
Oa
z W 0
w
-m
0
1.0
z .
$
0.I -..
I
1
I
I
0.1 INITIAL
I
1 I 1
II I.0
AQUEOUS
1
t
1
I
I
I
I 1 1
1
I
10 NITRIC
ACID
I00
CONCENTRATION,
~
Figure 32. The effect of Inltlal uranium conoentratlon on the extraotlon ofâ&#x20AC;&#x2122;uranyl nitrate by 20 volume per cent TBP In CC14 a6 a funotlon of lnltlal aqueous nltrlc sold oonoentratlon. After R. L. wore,
reference 396.
Condltlona: Equal volumeEI of phases shslcen In a water bath at 250c. dllutlon of the eolvent.
Duncan and Holbur-
the distribution of uranlum,inltlally
have meaaured
present In 1.2 to 1200
mlcrograme per llteq between 2C@ TBP in kerosene and nitrla acid solution.
Although the results were somewhat erratic,
it was generally shown that the partltlon ooefflolent la nearly conBtant over thiB range of uranium concentratlone.
132
The extmictive capacity of TBP Is affected considerably by the choice of dlluent.
T.aub~
extracted U(VI), Np(IV),
NP(VI), and Pu(VI) from 5~ HN03 aqueous solutions with 0.15~ TBP dlsaolved in a number of solvents, including benzene and chloroform.
Larger extraction coefficients were obtained for
all the elements tested with benzene rather than chloroform as dlluent.
In the case of uranium, the difference Ln au was
greater than ten-fold.
Little difference in extractlve
capacity was observed with TBP Cllluted by benzene or carbon tetPachloride. al.=
Similar results were obtained by Dizdar, et
Uranyl nitrate (0.003811)was extracted from 2~nitrlc
acid solutions by various concentrations of TBP diluted with oarbon tetrachloride~ xylene, kerosene, hexane, clibutyl ether, dlethyl ether, and isopropyl ether.
The partition coefficient
was found to increase with inore~ing
!t!BPconcentration to a
maximum for pure TBP.
For carbon tetrachlorlde and xylene
the maximum value was already attained at 40 mole per cent TBP .
The other diluents are listed above in the approximate
order In which they inhibit the extraction of uranium by TBP. Differences In au,for various dlluents,were found to become smailer with increased uranium concentration.
Bruc~
has
found that the extraction of fi~sion products Is alao affected by the choice of dlluent. The extraction of uranium by TBP Is considerably enhanced by the presenoe of salting-out agents in the aqueous ~ase .400-406
The results or Sat=
are given in Table IX
and figure 33. The extraction of uranium by TBP decreases with Increased temperature.Q@Q Phosphate, sulfate, and fluorlde ions reduce tion of uranium by TBP from nitrate media.~
the extrac-
Uraniumis
extraeted from chlQride solutlon but leeB efficiently than from nitrate solution.
Silica causes poor phase separation
133
Table XX.
Extraotlon of uranyl Nitrate by TBP Using Various Nitrate Salting-out Agents.~
Salting-out agent
Percentage extraoted C)yHN03
lg HN03
Z& mo~
6~ HN03
2.96
82.10
95.52
97.10
NH4N03
70.00
92.30
96.50
97.40
LINO
73.05
94.60
97.50
97=95
72.50
93.00
97.10
97.80
KN03
65.00
90.50
96.00
97.10
ti(N@i
86.02
97.50
97.70
99.00
M3(N03)2
84.35
97.20
97.50
99.40
Ca(N03)2
82.W
96.60
96.60
97.50
Zn(N03)2
79.75
98.05
$)8.10
99.40
A1(N03)3
99.90
99.60
98.20
99.50
Fe(N03)3
99.80
99 50
98.20
98.90
(W+)
3 NaN03
●
~ After T. Sate, referenue 406. Organic phase - 1% TBP in kerosene. Aqueoufl phage - 5 g/1 uranyl nitrate, ~ salting-out agent, initial acid concentration indicated. Equal phase volumes Aaken together for 30 minutes at 20°C.
and the formation of emulsions. Uranium may be re-extracted from TBP by contact with sodium caxbonate so~ution. ~
Ammonium sulfate, sodium sul-
fate, and urea solutions have been used satisfactorily.—409 Water or hydrogen peroxide 18 ineffective for TBP containing considerable nitric acid.~ The distribution of nitric acid between aqueou~ solution 412 and 10C@ TBP is demonstrated in figure 34.—
The. distri-
bution of various metal nitrates between TBP and nitrate
134
100
95
90
AMOUNT
OF
NITRATE
SALTING-OUT
AGENTS,
~
Figure 33. Effeot of nitrate salting-out agent8 upon the axtractlon of uranyl nitrate at U_ initial nitric! acid concentration. After T. sate, ra?erenoe 406. 2onditioneI: Org.snla phase - lx TBP in kerosene. uranyl nitrate, ~ HN03, saltingAqueous phaf3e - 5 @ ~ut agent concentration Indioated. Equal phase volumes shaken together for 30 minutes at ,20â&#x20AC;?C. 135
L
1
1
1
m
I
Symbol
n1 I I
I
1
1
1 kl
nII
I
1
1
1 I 1
I
m
Acid
x
HF
0
1
v
HCI04 I-ICI
A
HPd03
o
H#04
0
“.”.
0.01
n
1
1
n
1 1
1 11
10
1.0
0.1 ACID
1
CONCENTRATION,
AQUEOUS
PHASE,
J4
Figure 34. The distribution of mineral aalds between 10@
TBP and aqueous
Bolution at 250c. After E. Heafbrd and H. A. C. McKay, reference 432.
~olutlonshas been extensively Inveatlgated.
The extraction
ooefflcients of some actlnlde elements are plotted against aqueous nitric aoid ooncentratlon In flguree 35 and 36.Ishimori snd Nakamur~
have also measured the partition co-
efflcienta of Hf, Th, Pa, U(VI), Nap,
and Pu(IV)(VI)
at various equeous nitric acid concentrations.
Figure 37
repre8enti3 the partition coeff’lclent of several fission pro. ducts aa a function of the nitric sold concentration. 418-420 136
I00
L
I
I
I
I
I
I
I
I
i
I
1
10
—1.0 .
7
4
/
..7 .
WV)
‘i
0.1
0.0!
0.00! ‘L--l-L OB
2
3
4
5
6
7
8
9!0!1!2
[HNOdw Figure 35. The partition coefflcle~t of actlnlde nitrates between 19$ TBP in kerosene and aqueous solution as a function of eauili@U (VI), ❑ Np (VI), ❑Np -(IV), b;ium nitric acid concentration. APu (VI) at 20°-230C., after K. Alcock, G. F.-Best, E. Hesford, H. A. C. McKay, reference 413. Apu (IV), VPU (III), at 250c. or 20-P3°C., a?ter G. F. Best, H. A. C. McKay, P. R. Noodgate, reference 414. oTh (IV) at Ps°C., after E. Hesford, H. A. C. McKay, D. $cargill, reference 415.
137
-,
A
Am(!i!]
I
0.01
I
❑
I
01234
I
I
I
Gf(lll]
1
S678
1
1 1 9101112
I
IY””ih Figure 36. The distribution of trivalent actlnldes between 10Q% TBP and aqueous solutlon as a function of equilibrium nitrio sold concentration at 25”c. After G. F’.Best, E. Hesford, and H. A. C. McKay , reference 416.
The extraction of rsre earths, Y, Zr, Sc, Th,and Am by TBP from aqueous nitric acid solutlon haB been Investigated by Peppard and co-workers.
421,422
Iodine 18 extracted.
It
forms addition compounds with oarbon-unsaturated compounds in the solvent.
The extraction of Iodine 16 mlnlmized by
keeping it in a reduced state and by careful selectlon of T’BP diluents.~
Ruthenium is also extracted byTBP.
Its
extraotlon may be reduced by inoreased solvent saturation with uranium, by digestion in a nitrate solution of very high ionic
138
,.
I 00
k
I
I
I
I
I
I
i
I
I
I
i
I
EU-100 % TBP Y- 100% TBP Ce[!ll)100% TBP La-100% Nb- 100% Nb - 20%
10
TBP TBP T13P
zr-19%
TBP Y- 19’% TBP
1.0
0.1
0.01
0.001
! 01
1
1
I
I
I
23456
I
I I I 7’891OIII2 I
I
I
[HNOd”~. Figure 37. The distribution of fission product elements between TBP of several concentrations and aqueous solution as a function of equlll.brlum nitric acid concentration. Zr, after K. Alcock, F. C. Bedford, W. H. Hardwlck, and H. A. C. MCKSY, reference 418. y, ~~ Ce, EU, after D. Scar$ill, K. AlcockbJ.a:~e:l;tcher, E. HesfordJ . J. Hardy and and H. A. C. McKaY, reference 419. Tracer, carrier-free or D. ScarRill, reference k20. Condltlon~: with le~s than 1 g/1 of carrier used In all cases, Zr equllibratlons made at 20-23°C.; Nb, -20~c.; all other~ at 25°C. TBP diluted with kerosene.
139
strength, or by treatment with a reducing agent. = and Jelic@
and Sat=
Suelc
have studied the TBP extraction of
metal nitrates that may be used as saltlng-out agents.
The
order of extraction of 0.1 mg per ml concentrations of metal from 23 HN03 solutions by 2@
TBP/kerosene with no uranium
423 present is Bi > Co > Cu > Fe > Zn > Cd > Ph.—
The partltlon
coefficient of bismuth under suoh condltlon8, with equal phase volumes, is about 0.1.
The results of Sat=
are listed In
Table XXI. The partition of uranium and other metal nitrates between trlbutyl phosphate and aqueous solution Le affected –. ....L . -.– greatly by the presence of nyarolyals ‘-–’---”–-”-proaucr.s In me organzc
Table XXI.
Extraction of Metal Nitrates by TBP.~ Percentage extraoted
Metal nitrate
HN03
Oy HN03
1~
0.050
0.025
Ca(N03)2
0.118
0.064
zn(No3)2
00005
A1(N03)3
0.004
0.003
Fe(N03)3
0.010
0.008
LiN03 NaN03
Imo
3
CU(N03)2 W(No3)2
— a After T. Sate, referenoe 406. nitrate at Inltlal Aqueous phase -5 g/1 uranyl nitrate and ~metal nltirlc sold concentration indteated. Organlo phaee - 19 TBP diluted in keroeene. Equal phase volmna? shaken together for 30 minutes at 20”C.
140
phase, eg. , mano- and dl-butyl phosphates.
These products
may be eliminated by washing or boiling the solvent with an alkaline solution.
Two proaedu~es for the removal of TBP
ImpurTtles are given. Procedure 1*:
TBP is purlfted by bolllng with a dilute caustic soda solution. Add 500 ml Of O.~ NaOH solutlon to 100 ml. of Impure TBP . Diattll at atmospheric pressure until 200 ml of distillate have been colleoted. The remaining TBP is washed repeatedly with water. It may be dried by warming under vaauum.
procedure 2@-:
TBp Is stirred with an equal volume of 6M HC1 at 60”c for 12 hours. The separated ‘I%P is cooled to room temperature and scrubbed with two equal-volume portions of water, three equal volume portions of 5$ aqueous sodium carbonate solution, and three equal volume portions of water. The resultant TBP Is dried by heating to SO”C under reduced pressure.
Agueous dhloride s~stems. - --------------_-----
Uranium Is extracted from
chloride solutlon as U02C12 “ 2TBP although higher uranyl ahloride complexes may also be extracted. 426-428
The par-
tltlon of uranium between TBP and aqueous hydrochloric acid solutlon is shown In figures 3-
end 39.W
The effect
of uranium concentration on the dlstributi.an Is given in 428 figure 40;— 41.=
the effect of TBP conaentratlon, In figure
In Table XXII, the influence of saltlng-out
agents on the extraction of uranyl chlorlde by 3@ dlbutyl ether Is recorded. ~
TBP in
The distribution of hydro-
chloric acid between TBP and aqueous solution is shown In 412 figure 34.—
In figure 37, the partition coefficients of
Pa, Th, Zr, .andSc are plotted as functions of aqueous HC1 concenjn?ation.~
In f@ure
39, the partltlon coefficients
of Nl, Mn, Cu, Co, Zn, In, and Fe ~111) are similarly plotted.~ Ishlmori and Nakamura ~have
measured the partition aoeffi-
clents of Hf, Th, Pa, U (VI), and Np (IV)(V)(VI) as functions of aqueous acid concsntratlan.
141
Gal and Ruvar&c+~
have similarly
[â&#x20AC;&#x2122;+ciJ.q..M Figure 38. The extraction coefficient of U, Pa, Th, Zr, and Sc between pre-equilibrated 10@ TBP and aqueous hydrochloric acid at 22° + 2oC. After D. F. Peppard, G. W. Mason, and M. V. Gergel, referen~e 42$),and D. F. Peppard, G. W. Mason, and J. L. Maier, reference 422.
142
!00
I
10
1.0
0.1
0.01
L
0!
2345678910â&#x20AC;?1112
I-ICIaq., [1
~
Figure 39. The extraction coefficients of U, In, Zn, Cu, Co, Fe, and Mn between pre-equilibrated 10@ TBP and aqueous HC1 solutlon at 21 + O.l°C. After H. Irving and D. N. Edglngton, reference TBP and HC1 pre-equilibrated by stiming equal 430. Vondltlona: volumes together for about 10 minutes. Tracer concentrations or about 0.021jU and Cu used. Equal volumes of pre-equilbrated phases Btlrred together about 5 minutes.
143
‘.? * .’
I
,
,
I
,
t
n
1
I00
3
I
1
t
,
,
,
I
m
1
1
1
u ,
\
2-initiol U concentration
10
I
Figure 40., The distribution of U02C12 bgtween 10@
TBP and aqueous HC1
solution as a finctlon of uranium oonaentratlon” of the aqueous phase .
Curve 1 rep~esentO the partltfon with the equilibrium
aqueous uranium concentration plotted as abaoi~sa; curve 2* the partition with initial aqueous uranium concentration as abscissa; Wter
,
\
A. S. Kertes, and M. Halpern, referenae 428. Condltiona: Constant HC1 aoid mnoentration of 8.83M; equal phase volumes e~uillbrated for 15 minutes at room temperature, 18 - 22”c.
144.
i
I
1 1 1 1 111I I
I
, h 1 941dI
1 I # I I 1n, I
-1 7
1
%
TBP
Flmre 41. Fartltlon coefficient of uranium a6 a function of TBP concentration ~or various initial aqueous HC1 concentratlonB. 10.7FJ, 6.75~, and 1.02M HCl curves, after V. M. Vdovenko, A. A. Lipovskll, and S. A. N~kitina, reference 426. Conditions: TBP dissolved In benzene. ExtractIon made at room temperature using u233 . 4.6~, 5.9~ and 7.6M HC1 curves, after V. B. Shevchenko, I. G. Slepchenko, V. S. ~hmldt, and E. A. Nenarokomov, reference 427. Condltlons: TBP dissolved In CC14. Equal phase volumes (10 ml) mixed together for 30 minutes and allowed to stand for 12-15 hOurS. examined the partition coefficients of Fe (11)(111), U (VI), cd (II), Sr (11).. Zr (IV), Ce (III), RU (IV),and V (V). Aqueous s~steme. ----- ------perchlorate ------------
The distribution of uranyl
perchlorate between TBP and water at Z!5째C is shown in figure 42.%
Figure 43 gives the Wtltion
coefficient of uranium ~ ES z function of the aqueous perchloric acid concentration.
145
Shevohenko et al.-have
studied the extraction of uranyl
perchlorate in the preaenceof
HC104, LIC104, and NaC104.
The Baltlng-out capaoity of these aaltB Increases,ln the order listed.
The choice of TBP dlluent also affects the extraction
of uranyl perchlorate.
From an aqueoua solution of o.065~
HC104 and ~ was
NaC104, the extraction of uranium by 2.2013TBP ~ found to decrease in the following order of diluents:
Isoamyl acetate > n-butyl acetate > iaoamyl alcohol > toiuene > Xylene > benzene > carbon tetrachlorlde. TheJ dlstrlbutlon of perchlorlc acid between TBP and aqueous 412 solutlon is given in figure 34.—
!Ihepartltlon coefficients
of Th, Zn, pm~ Y, and Ce are plotted against aqueous perchlortc acid concentration in figure 44.% Table ~11.
Effect of Salting-out A@nts
Iahimori and on the ExtractIon
of Uranyl Chloride by TBP.~ a. u
Salting-out agent
0.03 NaCl, satld
2.85
KC1, satld
0.38
NH4C1, 5g
0.71
LIC1, 5FJ
0.90 17.6
HC1, 5FJ
5.06
cac12’ 2“5~ WJ12,
11.7
2.5H
23.8
‘1C13’ 1“67~
~ After Gal and Ruvarao, reference 431. Initial composition of organic phase - 3@ (v/v) TBP In dibutyl ether, sat’d with 1.22~_HCl. Inltlal composition of aqueous phase - 1.225FJHC1, &;~c::#2 . ‘ salting-out agent at concentration
146
1.0
I
r
1
1
u
1
# 1
1
1
1
,
I
1
1 ,
i
I
1
1
I
1
w
I
1
0. I
0.01
0.001 I 0.01
1
1
I I I
1
11
1
1
1
1
I 1 II
0.1 URANIUM
1
1
1
1
1
1
I.0
CONCENTRATION,
10
AQUEOUS, ~
Figure 42. TIME partition of uranyl perchlorate between 10@
TBP an?
water at 25”c0 After E. Hesford and H. A. C. McKay, referenoe 169.
Nakamura~l~ have studied the extraction of Pa, and Np (IV) (V) (VI) by TBP as a function of perchlorate concentration. Aqueous sulfate s~stems. - --------------------
Sulfate Ion Is normally con-
sldered an interfering ion in the extraction of uranium from aqueous solution by TBP.
Veereswararao, ~however,
found
that algnificant amountB of uranium may be extracted from sulfuric acid solution and that the extraction is “increased as the acid concentration is increased (figure 45).=
147
!
F
0!
I
I
I
I
1
1
1
I
I
1
I
1
I
I
I
1
I
1
I
I
I
1
234567’
8910!1
4
!2
Figure 43. The extraction coefficient of trace amounts of uranlumbetween 10@
TBP and aqueous solution as a function of equilibrium
aqueous HC104 concentration.
25°C.
After E. Hesford and H. A. C. MoKay, referenoe 169.
148
I
I
I
I
I
I
I
i
Th
10
1.0
01
234-567891,011
12
Figure 44. The dlstrlbutlon of Th, Pm, Ce, Zr, and Y between 100$ TBP and aqueous solutlon as a function of Inltlal equlllbrlum aqueAfter S. Sieklerskl, reference 433. Conous HC104 concentration. ditions: Equal phase volumes (15 ml) shaken together for about 20 minutes at 21째-250C.
149
I
I
I
I
I
I
I
I
I
I
I
I
I
1
1
1
1.0
0. I
0.01
I
01.234
1
‘56789
Fzgure 45. The partition coefficient of uranium between 3@
TBP (v/v)
In kero6ene and aqueou6 aolutlon as a function of equilibrium aqueous H#04
concentration.
After U. Veereswararao, reference 434. Conditions: Equal phase volumes (10 ml) equilibrated by shaking for 5 minutes at 18° * I°C. The presence of sodium chloride In sulfuric aoid solutior. augments the extraction of uranium by TBp.~
Molybdenum
and iron (III) are well extracted from fluchsolutions. Vanadium and iron (II) are poorly extraoted compared.to uranium.—434
The distribution of sulfuric acid between
TBP and aqueous solution is represented in figure 34.= Aqueous thloc~anate solution. . ---------- ---------------
pe~r*w ad
~enburg~
have studied the ef’feet of tkdocyanate Ion an the extraction of uranium from sulfage liquors by TBP. solution Oont.ainlng 1.5 ~1
of U308 =
Rrom an aqueous ~a~l
sulfate and.
2.1 &/l total Bulfate ooncentratlon at PH 1.5, the partition aoe~ficient of uranium varied from 3.5 to 100 as the thio~yanate to uranyl molar ratio was increased from 2 to 6. Twenty per cent TBP dissolved in kerosene wa~ used as extractant.
The partition Coefficient, au, increases with
Lncmeased TBP conoentrationp increases with increased PH, and dem?eases with inoreased sulfate concentration. Vanadium andiron
(III) are appreciably extracted by TBP from thio-
cyanate solutlons. extracted.
Copper, titanium, cobalt are weakly
Iron (II), cadmium , molybdenum, magnesium and
aluminum are essent’id.ly not extracted.
Phosphate ion may
cause the precipitation of uranium or complex formation when present in large amounts.
Okada, et al.=
report the ex-
traction of uranium by TBP, mesityl oxide, and methyl ethyl ketone from phoephoria acid solutions amonium
having 20 times as much
thiocyanate as uranium.
Tri-n-octylphosphine ..— —
oxide (TOPO)
Much of the work on thlB solvent has been reported by White and ao-workers.-437-444
Uraium
iS extracted bY TOPO
from nitrate and chloride solutions and to a smaller extent from sulfate and perchlorate solutions. It is essentially not 441 extraoted from phosphate solutions.-— The extraction of U, Th~ Bi, Mo, Zn, and Cr by O.l~ TOPO from aqueous solutions is given as a function of nitric acid concentration in figure 46; as a function of hydrochloric acid concentration in 440,441 figure 470——
Iron and titanium extraction curves are
also included in figure 47.
The extraction of over 40 ions
by O.1~ TOPO from hydrochloric, sulfurlc~ perchloric, and nitric a.oid solutions is qualitatively indicated in Table XKIII.~
Th e extraction of mineral acids by O.lM TOPO X9
441 a function of acid concentration is given in figure 48.— Uranium may be stripped from TOPO solutions by contact
151
o
!
2
3 NITRIC
789101112
456 ACID,
molori~y
Figure 46. Extraction of some metal Ions by O.1~ trl-n-octylphosphlne oxide from nitric anld solutions. After J. C. White, references 440 and 441.
152
I04
k Mo!ybden!Jfrl
,~3
I&
10
‘i
1.0
0.I
1’A ‘+
01
1
M’
1
1
1
23456789101!
12.
HYDROCHLORIC
ACID,
mOlarity
Figure 47. Extraotlon of metal ionB by O.%
trl-n-octylphoephlne
from hydrochloric acid solutlons. After J. C. White, references 440 and 441.
153
oxide
Table XXIII.
Extraction of Ions from Acid Solutions with O.l~TOPO
in
Cyclohexane.~ HN03
HC104
H2SQ4
HC1
Ion lM â&#x20AC;&#x201D;
p
@
llM
M
7E
lhl
7M
A~+3
N
N
N
N
N
N
N
N
~b+3
P
E
E
E
P
E
P
P
AB+5
N
N
P
N
P
P
N
N
~a+2
N
N
N
N
N
N
Be+2
N
N
N
N
P
N
N
N
B~+3
P
N
E
?
P
N
P
N
B+3
N
N
N
N
N
N
~d+2
P
P
E
E
N
N
~a+2
N
N
N
N
N
N
~e+3
N
N
N
N
N
N
N
N
~r+6
E
E
E
E
E
E
E
E
CO+2 CU+2
N
N
N
N
N
N
N
N
N
P
N
N
N
N
N
N
m+3 ~r+3
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
~+3
N
N
N
N
N
N
N
N
~d+3
N
N
N
N
N
N
N
N
~a+3
N
E
N
E
N
E
N
N
~e+4
?
P
?
P
?
P
7
7
Au+
E
E
E
E
E
E
E
P
&4
E
E
E
?
E
E
P
P
Ho+3
N
N
N
N
N
N
N
N
~n+3
P
P
E
E
P
N
N
N
~e+3
E
E
N
N
N
N
N
N
~a+3
N
N
N
N
N
N
N
N
N
N
N
N.
N
N
N
H ~
?
N
~b+2 m+2 +2 HE ~o+6
N
N
P
N
P
?
N
N
N
E
E
E
E
E
E
N
154
P
Table XXIII.-Contlnued. HC104
H2S04
HO1
Ion
11.M —
~
~
HNo
lM
7g
lM —
. #3
N
N.
N
N
N
N
N
N
Ntw
N
N
N
N
N
N
N
N
Pd+2
N
N
N
N
N
N
N
N
pt+2
P
P
P
N
N
N
N
N
~+3
N
N
N
N
N
N
N
N
RU+2
N
N
N
y
N
r
N
N
~m+3
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
7
?
P
P
&+ ~r+2
N
N
~b+3
N
N
N
N
~h+4 ~+3
N
N
N
N
N
N
N
N
~n+4
E
E
E
E
E
E
E
E
~i+4
N
E
P
E
P
E
P
P
@6
E
E
E
E
E
E
E
E
@4
N
E
N
N
N
N
N
N
~+3
N
N
N
N
N
N
N
N
~+3
N
N
N
?
N
N
N
N
~n+2
P
P
N
N
N
N
N
N
~r+4
E
E
E
E
E
E
E
E
E = complete extraction
P = partial extraction
~ After J. C. White, reference 438. Equal phase volumes equilibrated 10 minutes.
155
N
5
no extraction
+
1.0
0.1
1 *.,.
~
01234567
8
ACID CONCENTRATION EXTRACTED SOLUTION
OF (~)
Figure 48. Extraction of mineral acids by trl-n-octylphosphine
oxide.
After J. C. White, reference 441. Conditions: Aqueous phases - acid aolutlon of indicated molarity. Or anic phase - 10 ml of O.~ TOPO in cyclohexane. Vva-l. 3 with add
(1-LFS H3P04, or concentrated (NH4)2S04 solutions
at pH 2), hydroxide (NaOH or NH40H), or carbonate [(NH4)2C03 or N~CO
] solutions. * Sodium carbonate is the most 3 effeotive stripping agent.
~etrapheny lphosphonium chloride (TPPC) A re~ent study has been reported in which uranium was extraated Into chloroform as the tetraphenylphosphonium uranyl
156
446 trlbenzoate complex.— form by benzolc aatd.
Ur~yl
10n WL3B converted tO an &tIIiOUIC
Tetraphenylphosphonlum
chloride was used
~; extractant. The extraction of uranium v?aa found”to depend .. u~n plijTPPO concentration, and uranium conc!entratlon. At ‘2H 3-9P the ext??actton of u??anlum W*S nearly quantitative. — The Pw?tltlon ooeffialent, au, was increased with increased TPPC concentration and was decrewed The deorease in ~
concentration.
with inareased uranium with Increased uranium
concentration was observed with a constant ur’anlum-to-TPPO molar ratio.
At 250&and
pH 5.2= zinc, zirconium (niobium),
and ruthenium were appreciably extraoted (-10-2@
compared
to 10C@ for uraniu”m). The extraction of zino and zirconium may be depreOsed by the,use of a completing agent, EDTA, in solutlon. ACIDIU ORGANOPHOSPHORUS COMPOUNDS Uranium is efficiently extracted by acidic organophosphorus compounds whioh include di- and mono- alkylphosphoric aalds , (H0)(R0)2P+0 acids, (H0)R2P+
and (H0)2(RO)P~0;
dialkylphosphinic
o ; alkylphosphonic acids, (HO)@P~
dialkyl~ophosphorio
acids, ~P207.
O; and
The latter acids are
discussed separately. Table XXIV compares the extractive capacities of several dialkylphosphorlc,
dialkylphosphinic, and mmoslkylphosphoric
acids for uranlum.—3W
The ability to extract uranium, within
a given class, appears to decrease with inoreased branching of the allcyl ohaln near the phosphate group. tihe.reagent deareases roughly in the mme
The acidity of”
order. =
mere
comparisons can be made for the same alkyl group between classes of reagent, the extraction coefficient of uranium increases In the order dialkylphosphoric acid < dialkylphosphinic acid < monoalkylphosphorio acid. The choiae of diluent affects the extraction of uranium.
157
For
Table XXIV.
Ilxtractlon of Uranium by Acidic OrganophosphorUs Reagents.~ Uranium extraction coefficient, au Kerosene Carborr tetrachloride
Dlalkylphoaphoric
aaids
n-octyl 3,5,5-trlmethylhexYl 2-ethylhexyl 2-ethyl-4-methylpentyl 2-propyl-4-methylpentyl octyl-2 dilsobutylmethyl Dialkylpho6phinic
450 260 135 90 60
o ? 1; 11 2
10
acids 300 300 18o 160 120 30
y-phenylpropyl phenyl-2-ethylhexyl n-de cyl n-octyl 3,5,5-trimetU~eVl 2-ethylhexyl Monoalkylphosphoric
.
acids 580 >1000 >1000 450
n-octyl 3,5,5-trimethylhexYl 2-ethylhexyl dlisobutylmethyl 2,6,8-trimethylIJcmyl-4 l-iBobutyl-h -ethyloctyl 3,9-diethYltrldeaanol-6
>1060 >1000 [) 6;0 600 550
~ After C. A. Elake, Jr., C. F. Baes, Jr., K. B. Brown, C. F. Coleman, J. C. White, reference 302. Aqueous phase: o.5~ so;-, pH 1, 0.004~ U(w) Organ~c phase: O.~
Initially.
reagent in solvent indicated.
Temperature, 25째Q; V#la,
1.
dialkylphosphorlc and dlalkylphosphlnlc acids, au generally 302 Inareases as the dielectric constant of the solvent increases ----For monoalkylphosphoric
acids, a reverse trend Is indicated.~~~
The mechanism of extraction of uranium by dlalkylphosphorlc acids has been studied by various groups. X8,159, 3C2,447 At low uranium concentrations, the extraction mechanism appears to be consistent with the reactton ~02+ aq + 2(HDAP) ~= U02(DAP) ~+ 2H+ aq, 2 where HOAP representia dialkylphosphoric acid. .
.
However, in
158
,
organic solvents, dialkylphosphoric acids are largely iBsociated as dimers. 158,159,
448
On this basis, the reaction
U&2+’aq + 2(HDAP)2 X13= U02(DAP)2(HDAP)2 org + 2H+ La indicated.~-5~
(1)
The number of dialkylphosphate groups
associated with the uranyl iOn in equation (1) may be accounted
158,302
for by a chelate structure –
1
‘2R2 I /p\ o
o
0
H 0“ =.p/
4R2 At higher uranium concentrations,
. and viscosity
isopiestic
measurements indicate that polymeric uranyl-dialkylphosphate chains sre formed.~~8 The extraction coefficient of uranium by dibutylphosphoric acid, HDBP, is given in figure 49 as a function of nitric acid concentration.~~
The shape of the curve has been
explained by Healy and Kennedy in the followlng manner:—188 The initial decrease in ~ between O.1~ and ~ HNO is expected on the basis of hydrogen ion rep 2acement by U%+ ion, However, for ~ greater than 10 not enough HDBP is present in the or anic phase to give the monomeric species UO (DBP7 2(HOBP)Z demanded by equation (l). Inthisregfon, theextractlon meohanism is likely to be governed by the reaction xUO~
aq + (X+1)(HDBP)2 org = [U02(DBP)2]X2HDBP org + 2xH+ aq. (2) The shape of the extraction curve from 3M to 10~ HNO is similar to that obtained with TB~ and ind ? Oates a change in extraction mechanism. The likely reaction is
U02+ aq + 2NO~ aq + (HDBP)2 org = U02(N03)22HOBP org. 2 The decrease in ~ above 7~HN03 to the competing reaction
is probably due
(HDBP)2 org + 2HN03 aq = 2HDBP . FJN03 org. It is likely that mechanisms (2) and/qr)(3) also ocour to some extent at high acid concentratlona.
159
(3)
(4)
The extraotlon meohanism of dialkylphosphlnlc acids Is expected to be similar to that of dlallcylphoaphorlo aoids. The former are often found as dlmers In organic solvents and the paxtition coefficient of uranium, au, exhibits a power dependence on extraotant oonoentratlon at low uranium levels simtlar to that of dialkylphosphorio acids. z
~~o.
alkylphosphorlc and monoalkylphosphonio
aoids have been found
in larger polymeric aggregate. -“
partltl&
o~efflcient~
for these extraotants exhibit first to aeaond powel- dependencies on extractant oonoentratlon. E Interference ’to ursnium extraction by anions inareaaes in the order C104- < Cl- < SO~- <Po~-
.
Stripping 10 easenttally the Inverse prooess of extraction. Uranium may be stripped from dialslphosphoria
acids by oon-
tact with hydrofluorl~ sulfurlc, phosphorio,or even hydrochloric acids.
The stripping efficiency Is generally Increased with
lnoreased acid oonoentration.~ ~trippiw
Aummnlum or ~odlum carbonate
is erficient.~
Synergism.*
In a search for reagenta to modify kerosene as
the diluent for dlalkylphosphoric aoi.ds,** It was discovered that neutral organophosphorua
compounds provided a synergistic
enhancement of the uranium psxtltlon aoefflcient.
The en-
hancement ts increased” in the following order of neutral reagent: trialkylphosphate < alkyl dlalkylphosphcmate < dialkyl alkylphosphinate < trlalkylphosphine oxide. Table XKV llsts ~
for several synergistic systems. ~
The
reason for the enhanced partition coeffloient, au, has been — * Co-operative action of dlsarete agencies suah that the total effect is greater than the “sum of the two effects taken independently. **Kerosene is modified to prevent Separatlon Ofa diamlphostiate ~salt as a sepaxate phase when alkaline strlpplng is”u~~u; chaln alcohols have been uBed as chemical modifiers. These, however, depress the extraction coefficient of uranium and other metals.
16o
[
1.(3 ..-
I
I
I
I
t
I
I
I
I
I
I
I
1
I
I
1
I
1
1
I
01234!567
89 NITRIC
ACID
J
10
NORMALITY
Figure 49. Variation of ~
with nitric aald concentrations for 0.14~
dibutylphosphorlc acid in benzene using 20 ml organic phase, and 50 ml aqueous phase, and an initial uranium concentration Of
0.018&
After T. V. Healy and J. Kennedy, reference 188W
explalned on the basis of (1) the addition of neutral reagent totie uranyl-~lalkylphosphate ing3~
complex through hydrogei. bond-
or of’ (2) eliminating the need of monomerizing a male
of dimeric extracten~” equation (l)).
in the extraction mechanism
(see
A recent studY of the synergistic system,
thenoyltrifluoroacetone-neutral
organophosphoms
compound,
indicates that more investigation is necessary for a more’ precise explanation of synerglatic effectO.—451
Much of the
work done on synergistic syatema involvlng dlalkylphosphorlc acids iS S~
ized.in reference 452.
161
II
Synerglatla Enhancement of Uranium FXtractlon Coefficient.~
Table XXV.
% Organophosphoru~
reagent
Di(2-ethylhexyl) acid (D2EHPA)
phosphoric
Cons.,~
0.1
Reagent Alone
------ . -— In synerglsblc combination with O.ly I-E!EHPA .—.
135
Phosphates trl-n-butyl trt-2-ethylhe8yl
0.1
Phosphates di-n-butyl n-butyl di-n-ar@ n-amyl di-n-heql n-hexyl di-2-ethylhexyl 2-ethylhexyl
0.1
0.0002 0.0002’
0.1 0.1
470 270 1700 2000
0.1 0.1
0.0002 0.0003 0.0004 0.0002
Phosphlnates n-butyl di-n-butyl n-butyl dl-n-he~l
0.1 0.1
0.002 0.002
3500 3500
Phosphine oxides tri-n-butyl tri-n-octyl tri-2-ethylhexyl
0.05 O*1 0.1
0.0025 0.06 0.02
7000 3500 650
2200
870
~ After C. A. Blake, Jr., C. F. Baes, Jr., K. B. Brown, C. F. Coleman, J. C. White, reference 302. Aqueous phase: 0.5M SOf-, pH 1,0.004M U(VI) inttlally. Organic phase: Re~-ents In kerosene ~lluent. Temperature, 25DC.; V@a, 1. Di~2-eth@.hexyl) —.... —.
phosphoric—... acid (D2EHPA, HDEHP)
!l%ie reagent may also be known by a le6D descriptive neme, dioctylphosphate
(DOF).
The extraction of uranium by
D2EHPA Is reviewed in reference 453.
The effect of acid
concentration on the extraction of uranium by D2EHPA is shown in figure 50.~~
The uranium extraotlon curve for
D2EHPA from nitric acid Is similar
in shape, for the few
points given, to that for dlbutylphosphoric ””acldgiven In flare
49.
Figure 51 illustrates the effect of nitrate ion
on the extraction of uranium by D2EHPA.~ a
small
The presence of
amount of nitrate in an aqueous sulfate eolutlon in-
creases the extraction of uranium slgnlflCan.tlY. An increase i.ntemperature causes a decreaae in uranium extraction. E3.
162
100
1(’’’’;
10
1.0
I
HCI
0.1 [L
\
L
J
v HQS04 H#04 \:
0.0! ) 01
I
I 1 23456
1
I
1
ACID
I I I I 7$,91011121314
v
I
I
I
NORMALITY
Figure 50. Extraction of Uranlu by dl(2-ethylhexyl) phosphoric acid In kerosene from mineral acid solutlons. After C. A. Blake, K. B. Brown, and C. F. Coleman, reference 453. Condltlons: Organic phase - O.lM D2EHPA In kerosene, 2X (w/v) 2-ethylhexanol. Aqueous phase - 1 g~/1 for all acid solutions except H3P04 In which cas? the U concentration was 100 ppm. Agitation ttme - 2 minutes. Vo/Va = 1 for all acids but HN03 In which Vo/Va = 2.
163
I000
I
I
I
I
I
I
J
3
4
5
6
7
I 00
3
10
t
I
o
I
2
NITRATE .- — CONCENTRATION,
~
Figure 51. The effect of nitrate ion on the extraction of uranium by dl(2-ethylhexyl) phoaphorlc acid. Curve 1 - initial pH = 1.5 1.85; curve 2 - initial pH = 0.5 - 0.75. Condltlona: O.olg D2EWA in kerosene (1.3X 2-ethylhexanol), 1 g U/l In aqueous phaae, Vo/Va = 2, 2 min. contact time. Curve 3 - 0.5g S04; pH= 1.2. condltionB: 0.05M D2EHPA In CC14, 1 g U/l in aqueouO phase, Vo/Va = 1, 20 min. cont~ct time. After C. A. Blake, K. B. Brown, and C. F. Coleman, reference 453.
The effect of diluent on ~
is given in Table XXVI.“w
The
enhanced extraction of uranium by D2HPA in synergistic combination with neutral organophosphorus reagents haB already been noted (Table XXV).~W-
The extent to which other Ions
are extracted la Lndioated qualitatively XXVIII .fl
164
In Tables XXVII and
Table XXVI.
Choice of Dlluent with Di(2-.ethylhexyl) phosphoric Actdo~
Diluent
% —
Kerosene
135
Eexane
110
Ca%on
2G
tetrachloride
Isopropyl ether
17
Benzene
13
Chloroform
3
2-Ethylhexanol
0.1
Cetanol-2
0.08
(capryl alaohol)
~ After C. A. Blake~ K. B. Brown, and C, F. Colemanj reference 453. O.lM D2EHPA, 0.004MU (VI), 0.5&SO&, PH = 1.1, Vfla = 1, agitati=n time = 10 min. (wrist-action shaker).
Dialk@-os~oric ..—.
,———
acidB
Dlalkylpyrophosphoric
acids are usecl in the recovery of
uranium from low-grade phosphate ores.
Nuch of’the work that
has been reported In project literature hag been summaiiized by Ellis,~by Coleman.%-
456 Lang, Ellis, and Bailes,-——— and by Brown and ~The acids are prepared Just prior to use by
adding alcohol to a slurry of P20~ in kerosene with stitrring and COOli”~.
A concentration of about O.i g P205 per m-luf
kerosene is optimum. ’55 --
A 2:1 mole ratio of alcohol:P205
is used to form the dialkylpyrophosphoric
acid.
A 3:1 mole
ratio should give about equal mole quantities of mono- and di-alkyl orthophosphoric acids.-4~G- The . rea,ctior2sare complex and mixtures of various phosphoric acids are formed. With pyrophosphoric acids~ uranium extraction IncFeases ’55 with carbon chain length from bv.tyl t~ cctyl,.-—
165
Nmyl
and
Table XXVII. Extraction of Netal Ions from Aoldlc Soluticns with O.1~ Dl(2-ethglha@) Metal Ion
phosphoric Acid in Cyclohexane.~
Sodium Chloride (I-M) Aumonlum Sulfate (1N) Sodium Nitrate (ly) pH 1.5 PHO P!+0.5 PH 1.5 pH 1.5 —. —
P
P
P
P
E N P N
E N P N
E
E E E E N N N E
E
E E E E E N N E
N N
N N N P N N N P N N N N E P P N N N E N N N N N E P E 73 E P P E
P N P N N N N E P P N N E N N N N E N E E E E N E
.
N N N P N N N P N N N N E P P N N N E N N N N N E E E E E P P E
E = complete extraatlon, P = p=tial extraotlon, N = no extractlcm, -= no te6t was conducted. ~ After W. J. Ross and J. C. White, referenae 454. Aqueous phase: 1-2 mg of Ion, salt at acmoentratlon Indicated, pH Indlaated. Organic phase: O.111D2HPA In ayalohexane. 5 ml portions of each phase shaken togetiierfor one hour.
166
Table XXVIII.
E%traatlon of Rare Earths from Chloride SolutlonB
with Di.(2-ethylhexyl) Phosphoric Acid In Cyclohexane.s Ion
PH 1.9
PH l.0~
.—l.&’ ‘r E
~+3
E
E
=+3
N
N
N
~e+3
P
H
N
~+3
P
N
N
PHO.5 ~.
PH 0.>
PH O —
P
N
N
N
N
N
N
N
N
N
N
Nd+3
E
N
P
N
N
N
~m+3
E
N
P
N
N
N
~+3
E
E
E
P
N
N
@3
E
E
E
P
N
*+3 ~+3
E
E
E
E
E
N N
E
E
E
E
E
N
~o+3
E
E
E
E
E
N
~r+3
E
E
E
E
E
N
~+3
E
E
E
E
E
P
~b+3
E
E
E
E
E
P
= complete extraction, P = partial extraction, N = no extraction.
M%er
W. J. Roee and J. C. White, reference 454.
Aqueous phase: 8t nd 0.5 &ml Tb+3~ 1 ~~ M3 Nd+~ S&$3eo#t~n Ho+3, ‘f 2 ~~ Ce+3; 0.2 mg/ml Y+~, La+j, Eu+~, Gd+~, Er+3; 0.1 mg/ml Yb~; 1 ml of standard solution, 1 ml 5~ NaCl, NaOH or HC1 to give desired pH In 5 ml of solution... organic phase: 5 ml of O.1~ D2EHPA In cyclohexane extraction ~“or1 hour. Without NaC1.
decyl give about the same extraction as octyl.~
No appre-
ciable difference in extracting ability was observed between pyrophosphoric acdckpre~tiwith
$33 octanol-1 or octanol-2---
Most of the studtes have been made with octylpyrophosphorlc acid (OPPA).
Pyrophoephorlc acids deteriorate fairly rapidly
with time at room temperature.
At elevated temperatures,
the rate of deterioration Is even greater.
Contact with
mineral acid causee pyrophosphoric acids to hydrolyze to orthophosphoric acids.
The rate of hydrolyses Is slower
with baelc solutions.—453 167
Kerosene is a satlsfkctory diluent for OPPA.~
The
acid is used In l-lC’# concentration. The partltlon coefficient of uranium, ~,
Is aonBldera-
bly higher with OPPA than with the corresponding mtiture of orthophosphoric aoldfl~OPA.
The psrtitlon coefficient i.sa
function of the oxidation potential of the acid.
With OPPA,
satisfactory uranium recovery can be made if the e.m.f. is -0.250 volts or greater. ~
Reduction of the acid Increases
the extraction of uranium conBlderably.
At zero to +100
volts. au is about twenty times that at -300 to -200 volts.5 The ~tractton %e(II)
of iron Is decreased In reduced Bolutlon, I.e.
‘%e(III)”
Uranium Is stripped from the organic solvent by precipltatlon aa uranou6 fluoride. Several papers have reaently appeared in open literature publications concerning the extraction of ursnlum by pyrophosphoric acids.
Zange~
has
shown that OPPA prepared by
the alcoholysia of P205 is a mtiture of several component. OPPA prepared in thiB manner was found to be more effective In the extraction of uranium thatipure dioatylpho@mric two orderR of magnitude.
acid by
The pure &cld was prepared by syn-
thesis,starting from POC13. In an effort to determine the uranium speaies extracted by OPPA, Grdenic and Kor~8 u(oct2P207)2.
The species, however, wae insoluble in ligroin,
the OPPA diluent. in a ratioof
have isolated the species
It was soluble in ligroin containing OPPA
one mole of U(IV)-salt emd 2 moles of OPPA.
This indicates U(Oct2HP207)4 is the extractable speoles.
The
same formula was obtained by determination of the uranium content in a saturated ligroin phase. Habashl~
has investigated the extraction of uranium
and other metals by OPPA from phosphoric aoid solutions. Uranium (VT) was found to be more highly extracted than uranium 168
(IN).
ThlB
is
SUPpPlBi13g h
VLeW of the increased extraction
of uranium from reduced acid ~olution mentlone6 previously. Also, cerlum (III) was found to extract more resdily than cerlum (IV). are
The partition coefficients of several metal Ions
given for variouB phosphoric acid concentrations in Table
with H Pou concen3 tration for all the metal ions tested except cerium. ‘The
XXIX .
The partition ooefficten~ decrease
extraction coefficients of both cerium (IV) and (III) pass through maxima in the region of 4~ H3P04.
The partition
coefficient of uranium is decreased by increased Initial uranium concentration.
The addition of Na3POq to the solution
uau~es au t.c increase greatly -.ap~ent~
by decreasing ~he
hydrogen iOn concentration in the aqueous phase.
Fluoride
ion interferes most seriously with the extraction of uranium by OPPA. Zangen@
has studied the extraction of uranium (IV)
from phosphoric acid by di(2-butyloctyl) pyrophosphate, BOPPA. AMINES AND QUATERNARY AMMONIIJM SALTS.
A large number of
amines~ quaternary snmmnium salts, and other organonitrogen compounds have been investigated as possible extractants of uranium.—— 461463
The physical chemistry of uranium extraction
by amines has been studied by McDowell, Baes, and Allen and Boir~ 46
464-468
Much of the above work has been summarized
by ColemanJ et al.— 304
More recently, Moor -has
reviewed
the extraction of a large number of elements, including uranium, by snines. The reactions involved in the extraction of uranium by 304 Organic amines have been reviewed by ColemanP et al.— tions of amines
solu-
extract acids from aqueous solution to form
alkylammonium salts R3N org + HX aq ~a
R3NHX org.
(5)
The amine salt in the organic phase can exchange its ion for another in the aqueous phase 169
!Ik3.ble XXIX.
Pertition Coefl’icientQ of’Sevmal
Metal Iom
E!etween O?PA and H3P04.9 Pa*titIon coe?flcisn$ Ion~”-
..— —
H3P04 concentration —
——
4FJ 2! w! ,.. — ..—....— ..— .... .... . 190
U(VI)
46
23
U(IV)
18.6
14.2
13.5
l’h(rv)
24
23
18
Fe (III)
18
8
5
8y .—
..—
20
13
Fe(II)
1
<1
V(IV)~
2
0.8
0.1
Ce(IV)
5
8
3
1
Ce(III)
7
22
4
2
<1
~ After F. Habashl, reference 459. The coefflclents, with the exception of u~(n)8 were determined from figures which appear in reference 459. ~ 0.4 mg metal Ion per ml; ~
OPPA in n-hexline; V@a
R3NIiX org + Y’aq $R3NHY
org + X-aq.
= 0.1.
(6)
The order of preferences for anions In the organic amine 601UtiOn is C104- > l?03-> Cl- > M04->
F-. 304 ..—
In this anion exchange representation, metals are then ex. t~aoted from aqueous solutionsin which they are present as anions or anionic complexes. U02+ 2 aq+w-a4+uox-aq. R3m
For exampIe, (7a)
23 \R3NHUO#3 \——
org + UQ-&-aq
org + X-. (7b)
This mechanism, however, is indistinguishable from one in which a neutral complex is extracted.
uo5a+2xR3NHX org + U02~
ai
A
uo2~
aq &R3~02X3
170
aq.
(8a) org.
(ah)
The factors that influence uranium extrawt.ion have been 304 ~tudted most extensively for anline-sulfate systems.—
me
effect of amine structure on the extraction of uranium
and
other metal Ions is Illustrated in Table XXX.=
Uranium
(IV) Is efficiently extracted byprimaryamtnes.
Theeffi-
cienoy decreases with secondary and tertiary amines.
With
uranium (VI) there does not seem to be much cofirelati.onbetween au and amine class.
With primary, secontiary,‘and ter-
tiary laurylamlnes, au(vl), under the cond.ltlons .gIven lr~ 304 Table X2X, is < 0.1, 80, and 140, re~pectively.— With primary laurylamine an emulsion Is formed.~
The extraction
of uranium Is also effected by carbon chain branching neax the nitrogen atom In tertiary amines (Table XXX). n-benzyl-branched-alkyl
Certait~
secondary amines have been found to
extract uranium extremely well.—--304 The uranium (VI) partition coefflclents of N-benzylheptadecylamlne, amine, N-benzyldodecylamlne,
N-benzyltetradecyl-
and N-(2-naphthylmethyl)
emines under the conditions outlined in Table ~,
>1000, > 1000, -1000, respeatlvelyO~o~
Thepartitlon
clent depends upon the aml.ne-dlluent combination.
dodecyl-
sxe 2000$ coefflThe effect
of dlluent on U’U(V1) is Indicated in Table XKK.~ The partition coefficient, %(w)’
is Influenced by
uranium concentration In that it changes the amount of free 304 amine Oulfate concentration.—
In sulfate solution, blsul-
fate complexes the amine more strongly than does sulfate.
The
uranium partition coefficient, therefore, decreases with increased acidity.~ ‘n ~(VI)
.=
Excess aqueous sulfate causes a decrease
The partltlon coefficient is also decreased
304 by increased temperature.—
ExtractIon isotherms Indicate
that four to SIX amine moleoules are a~sociated with each The number depends upon
uranium
Ion.=
amine used.
With vtgorous shaking, the partition coefficient,
~,
V=les
the partloular
approximately as the first power of the free amine 171
Table XXX.
Effect of Amine Structure on the Extraction of Metal SulfateE.~
Metal Ion
Partition coefflclent, a Tertiary Amlnes Seoondary Amines
Primary Amlnes Amineb 21.F81-
v ? fVfa’CStIII , Mn II ,FeII, Co \\ll 11 , Ni 11 , Cu II , Zh V(III) Fe(III) R.E,(III) Ce IV TI [1 171
~nk& -
<0.1
Dilaurylamine
Dl(trldeayl) amine
Amln 9-2~
Methyldl-ndecyle.ndne
Tri-iElooatylamlne
<0.01
@.ol
<0.01
<0.01
<0.01
<0.5
<0.5 <0.1
c).&&
4= 40 20
Trls(2ethylhexyl) amine
y)
%(0.51JS04) U(IV)
>1000 >500& 3000
V“v Vv[1 (pH2)~
-20
<1 -20
Mo VI ~ Mo [) VI (p~)~
150 >1000
200 >1060
<1
<0.1 <o 01
<0.01 <0.01
<0.01
<o*01
0.2
<0.1 200 <0 If <@
●
<1 -20
-20
400 >1000
>1000
>1000
50
90
u VI UVI UVI
H
<1
<1 400
-20 150
3 0.2
~ After C. F. Coleman, K. B. Brown, J. G. Moore, K. A. Allen, reference 304. 1~ S04, pH 1, ‘1 g metal ion per liter except as noted. V&a hydrocarbon diluent.
= 1, O.~_ amine in aromatia
, . ..’ Q
l-(3-ethylpentyl )-4-ethylootylamlne
.. ;NH ;’. .H
S trialkylmethylamlne, homologous mixture, 18-24 oarbon atoms
,,,,, ,. . . . . . ,,. NH ,,., .* H
, .,H“! .*N*, ●** ,’ #,B, ,-, ~ %efficlents at loadlngB of ‘5 g VOr ‘3 g Mo per liter of extractant. Extraction eoefflclents of theflemetals decrea8e as their concentration decreases.
~ bls-(1-lsobutyl-3,5-dlmethYl.heXYl) amine
~ Extraction from 0.5~ S04 6olution. ~Diluent
kerosene instead of aromatic hydrocarbon.
h – Diluent, chloroform instead of aromatic hydrocarbon.
●
eulfate concentrations =“U(VI) = k [~ (z amine) - n~ (U (~)) where n h&B avalue amine.~
orgl,
between 4 and 6, oharacterletlc of the
With H1OW equlllbratlon,in whioh the liquid-liquid
Interfaclal erea is strongly llmited and Interfaclal turbulence is prevented, nearly theoretimlly 468 been obtalned;— i.e., Cu (u)
ide&l results have
= k [~ (Z amine) - W_ (U (VI)) orgr..
Small amounts of foreign anions added to sulfate solutlons hinder the extraction of uranium more than Simll= amounts of added sulfate. IS S04 < P04 < Cl <F
The order of Increasing interference
~ < N03.
Effeotive separatlong between uran”hm and other metal Ions may be made by ohoioe of amine and/or dlluent (Table XXX).= Modification of the diluent with long-uhain alcohols or other modifiers affects the extractlve powers of the organic solvent phase.
A possible synergistic enhancement of au(n)
found with 3,9-dlethyltrldeoyl-6
has been
amine and di(2-ethylh&xyl)
phosphoric acid.= The emine extraction of uranium (ti) from aqueous phosphate or fluorlde solutions is qualitatively similar to that from sulfate solution.
Uranium Is extracted from relatively 10W
anion concentrations.
As the latter oonaentration is in-
creased, au is deareased. ~ or nitrate solutions.
The opposite is true
for chloride
Uranium extraction is Increased aflthe
concentration of either of the latter two anions Is increaaeh 304 Uranium may be stripped from the amine ,solvent phase by a number of methods.
Uranium extraoted as the.amine-sulfate
complex may be stripped by contact with a nitrate or chloride solution.
Alkaline stripping with sodium carbonate results
“in an aqueous uranyl tricarbonate aolutlon. dium hydroxide formprecipltates
Anmonlum or so-
that are dlffioult to handle.
A slurry of magnesium oxide causes uranium to precipitate .
174
as a magne6ium polyuranate. E Trl-n-octylamine
(TnOA)
The psrtitlon oQefflclents obtained by Keder , et al.=â&#x20AC;&#x2122; ~for
the extraction of actlnlde metals fbomnltric
acid
solutiomby
10 volume percent TtiOA In xylene are given in
figure 52.
Carswell~
hae studied the extraction of uranium
and thorium by 0.2~ TnOA in toluene$ alsos from nitric acid aolutlon.
Thorium appesrs to be more strongly extracted than
urantum in the latter system.
Uranium, however, is extracted
Practically to the same extent in both sy~tems for acLd.conoentrationa up to 6~. The extraction of uranium from hydrochloric acid solutions by TnOA In CC14 hae been studied by Blimt and T&emlllo& The
extraction
slmll~
curve as â&#x20AC;&#x153;afunction of HC1 concentration is
in shape and magnitude to that for trlisooctylamine
plotted in figure 53. Allen and oo-workerm
have made fundamental studies
on the extraction of uranium from sulfate solution by TnOA. Extraction of uranium from acetic acid solution ~y TnOA in Am$co D-95 appears to be Intermediate between extraction from sulfuric and phosphoric acide on one side and hydrochloric and nitric acids on the other. &4 Triisooctylamine
(TiOA)
The results of Moor-
for the extraction of uranium
(VI), thorium, and fission products from hydrochloric acid solution by 5$ TiOA in xylene are presented in figure 53. The extraction of strontium-85 is negligible from 2-1~ Americium (III) amd curium (III) are not extracted.
HC1.
Elements
which are extracted include Fe(III), CO(II), Zn(II), Hf(lN), V(V), Pa(V), Cr(VI), Mo(VI), U(IV), Np(VI,V,IV), and Pu(VI,IV) in addttion to those shown in figure 53.
The extraction of
Iron, vanadium, and ohromium may be suppressed by reduction to a lower oxidation atate.
Ruthenium remains in the organic 175
‘O’r—’——— Pu(lv)
,U
Np(v)(o
+-
x 10%
z u
10
❑
1.0
0.I
““,
LL——J——
0
1
2
3
I+N03
4
56
7
8
CONCENTRATION,
91011 ~
FUW7.W 52. The extraction of actlnlde Ions by ten volume percent trl-n-octylamine In xylene from aqueous nitric acid solution. After 1 W. E. Keder, J. C. Sheppard, and A. S. Wilson, reference 472 and 2 A. S. Wilson and W. E. Keder, reference 473. [1 Condltionfl: (1) Ten volume percent TnOA Inxylene were stirred with en equal volume of nitric acid of the desired composition for 3-5 minuted at room temperature (-25°C.). Phases were aepsrated by centrifi,gatlon after contacting. (2) !Jranium (IV) data only. Aqueous solutlons were prepered at eaoh nltrlc acid concentration by,dllutlon of a stock solution which was -lM U(IV), O.lM FL2104P and ‘lM Zn(II). Solutions for ext~action expe~iments were 0.7t15M U(IV). TnOA was contaoted by an equal volume of 12~ ~03 followed by three contacts of one volume each of the nitric acid concentration used. Equal volumes of aqueous and amine solutlons were contacted at room temperature for 5 ml~tes. Phases were separated by —. oentrif’ugatlon.
176
100
10 t
!.0
0. I
0.01
0.001
/ â&#x20AC;&#x2DC;Iâ&#x20AC;&#x2122;r
I
01
I
I
I
I
I
I
I
I
I
2
3
4
5
6
7
8
9101112
1
I
I
Figure 53. The extraction of u233, Th2j0, and fission products by 5$ (w/v) triisooctylamine in xylene as a function of HC1 concentration. After F. L. Moore, reference 475. Conditions: Equal phase volumes extracted for two minutes at room temperature (240c.).
177
phaae when washed with O.1~ HC1 solutlon. Into the aqueous phase.
Uranium Is stripped
Excellent extraatlon (>9@)
of macro
snounts of uranium (6o.4 mg U/ml initial aqueous concentration) can be obtained from 9~ HC1 with 20# TiOA In hexone. Moor-
haa a160 Investigated the extraction of uranium
(VI) from aaetlc acid solution byTiOA.
Extractions were
carried out in the same manner as those from hydrochloric Aqueous solutlonB of varying
acid solution (figure 53).
acetic acid concentration containing 2 x 104 alpha cuunts per minute per ml of $33 volumes
tracer were extracted with equal
of 5% (w/v) TiOA In xylene.
It was found that maxi-
mum uranium extraction (>90@) Is obtained from 0.5~ to ~ acetic acid Bolutlons.
The addition of S(v/v)
butyl cello-
solve to the TiOA-xylene solution inhibits foaming during the extraction process.
By increasing the TIOA concentration,
macro amounts of uranium are efficiently extracted.
Greater
than 95$ stripping may be achieved by contacting the aminexylene phase with an equal vohna
of o.5~ ~03,
~
H.#04,
6H H2S04, 1~ NH4HC03, concentrated NH40H, or 0.25~ HF-O.25~ HN03 solution.
From 0.5&~
acetic acid solution, ruthenium
(11.5%), zirconium (27.%%), and niobium (11.1%).are extracted. Separation IS made from strontium (alkaline earths), cesium and europium (rare earths), plutonium (III) (trivalent actinides), thorium, protactinium, hafnium, tantalum, iron, lead, nickels Oobalt, manganese~ chranium (111)9 aluminum, aopper, zinc, bismuth, tin,and antimony. w
The
~electivity~y
be improved if the uranium is first precipitated by hydroxide, dissolved with ~ viously described.
acetic acid, and then extraoted as preIron hydroxldeâ&#x20AC;?iB used to carry imace
~ amounts of uranium in the precipitation step. Other amine extractants. Ai3 stated at the beginning of this section, many orgaqonitrogen oompounds have been investigated as extractants of 178
uranium.
A large number of these invest igatlona are reported
$.nORNL reports (eg., ORNIJ-192&,
ORNL-209@).
For
further Information, one may refer to these reportB, the swnmarle83
04=461-463
previously mentioned, or the review by
F@ore.=
\,
Quarternary ammonium salts. The enhanced extraction of uranS_am by hexone containing tetrabu@laumionium nltrat &
or tetrapropylammonlum
has already been noted [see Hexone). Hultgreti
nitrat~
Haeffner, Nllsson,and
have also used tetrabutylammonium
nitrate to
extrsot uranyl nitrate with chloroform. Quaternary anmmlum
salts, unlike amines, may be used to 477,478,480 extract uranium from alkaline carbonate solutions. The Robin and Haas compound Quaternary B-104* converted to the carbonate form has been used succeaafully to extract uranium from aqueous solutions having carbonate concentration one molar.=
Amaco G done
up to
or modlf~ed with a long-ohaln
aloohol, tr%clecanol~ and kerosene modified with trldecanol have been used as dtluents.
The aloohol modifier Improves
480 both the phaae aeparatlon time and the extraction coefflctent.— The psrtition coefficient exhibits a negative two power dependence on carbonzte concentratio~
in accord with
the reactio~ 2(R4N)2C03 org + U02(CO~)~- ~+
(R$N)4u02(c03)3 ‘rg + 2co;-
aq.
(9)
The extraction coefficient la virtually Independent of the bicarbonate concentration with the carbonate-bicarbonate 480 total concentration held conatant.—
The coefficient is 480 decreased by an increase In temperature.— Uranium may
be atrlpped from the organic phase by solutions of HC1, HC1-NH4C1, HN03, and lDJ03-NH4N03.w
Nitrate aolutlona
●
An Isopropanol solution of dlmethyldlodecylammonium 179
chloride.
exe more effective than chloride. ~. NJ
Sodium hydroxide
(2&
480 may also be ueed as a strlpplng agent.— 481 Clifford, et al.— report the extraction of uranium
from aqueouB carbonate Boluttons by (1) forming a singly charged anion, UO&,with tracting this
anion
charged cation.
a uomplexlng agent, and (2) ex-
Into an organic ~olvent with a singly
-tractions
were obtained with benzoin 2-
oxlne, cupferron, hydroxylamine, peroxide, pyrogallol, and 8-quinolinol
(oxine).
The latter was u8ed for further study.
Arquad 2C, R’#(CH3)2Cl, where R’ is about a 16-carbon chain, was found to be the most effective extractant teEted. was found to be the most effeotive solvent tested. gave no extraction.
Hexone
Kerosene
With oxine as aomplexlng agent, the
extracted species was identified as R4NU02(OX)3.
The ex-
traction coefficient of uranium was found to increaae with Increased pH; to Increase with Increased oxine concentration and with increased R4NC1 concentration
(to an OPtimUm value);
to dec2eaBe with increased carbonate concentration. traction coefficient, ~,
An ex-
of 10.9 was obtained by ext~actlng
two volumes of an aqueous solution containing 0.0~U02(N03)2, Om~~
NyC03,
0.04~ NaOH, and 0.02~ Arquad 2C with one volume
of hexone containing O.100~ oxine.
Both uranium and oxlne were
removed from the organic phase by fltrong acida.
Sodium bi-
carbonate was found the most efficient stripping agent on a counter-current basis. c“ ~IC
ACIlX3.
H8k-Bernstrom 1%$482 uranium
ha
studied the extraction
Of
(VI), thorium, and lanthanum by several carbo~llc
aOidB: salicyllc, mthoxybenzoic, clnnamic.
3,5-dlnltrobenzolc,
Table XXXI llsta the pH at which
and
50 percent of
the metal Ions are extracted from perchlorate solutions by
O.lg solutions of the carbo~lic form
acid in hexone.
Chloro-
was found to be a Poor solvent for the extraction of 180
Table HI.
pH for 50 Percent Extraction of U(VI), Th, IA by Carbo~lic
Acid.~
Acid
PH so U02+ 2
m~
~a3+
Sallcylic
3.1~
3.3+
4.9+
Methoxybenzoic
3.@
3.&
3,5-DlnltrobenzOic
2.7+
2.8$
4.389
Cinnamic
3.6&
3.07Q
6.1#
~ After B. H&-Bernstrox,
references 138, 482.
Aqueous phase: metal concentration, 10-5M Th or 1A, 10-3~ U; ionic strength, O.lM ad~usted by the add~tion of NaC104; pH adjusted with Na6H and HC104. Organic phase: O.1~ carboxylic acid In hexone. v~va , 1; temperature, 25”c. ~ Lag a = O, reference 138. ~ Calculated from data given i.nreference 482.
the metals by the carboxylic acids studied. studied the extraction of U(VI),
Cole and Bro&have
Th, Hf and Zr from aqueou~ nitrate solutions by sallcyllc acid in furfural.
Satisfactory separations between uranium
and thorium were obtaine~ depending largely upon the two metal concentrations. 484 Sudarikov, et al.— have studied the extraction Of U (VI), Th, Ce, La, Y, andSc cylic
aotd In isoawl
from aqueous solutions by sal$-
alcohol.
The uranium complex was ob-
served to extract at PH 1.5 and to be completely extracted at pH 2.5 tO 5.0.
Up to pH 6.5, au was found to decrease from
100 to 0.3-0..4 and to remain Mills and Whetsel ~have
unchanged at higher PH values. extraoted uranium’
per~luorobutyric acid dissolved In diethyl ether.
181
with
l?he Qhelating figentadescrlbed below are
CE@XJLTIMG AGE-.
listed In the same general order aa they may be found in the book by Morrison and Freiser. E 0
o
Aoetylacetone, CH3 - ~ - CI$ - ~ - CH3
The extraction of both uranium (VI) and (IV) from perchlorate solutions with acetylacetcme ae chelating agent
The percentage extracted is
been investigated by Rydberg.
given as a function of equilibrium PH in flares -C for the t&ee respectively.
has
54A,-B) and
solvents, chloroform, benzene, and hexone, The extraotlon of other actinidee, fission
products, and hafnium is also included In the figures. -J â&#x20AC;&#x201D;486-488 Strontium and potassium are poorly extracted by acetylacetone into chloroform. ~
Lanthanum and samarium
are poorly extracted by the chelattng agent into all three solvents.3 Krishe*
has Investigated the extraction of uranium
(VI) with acetylacetone used both as chelating agent and solvent.
â&#x20AC;&#x2DC;The results ere given in figure Sw
together with
the extraction curves of several other metals.
The effect
of masking agents, ethylenedhminetetraacetate,
fluoride,
and tartrate, on the extraction of these metals Is given in figures 55~4
and~,
respectively.%
The extraction of uranium by acetylacetone-chloroform in the presence of sodium chloride and EIYTA has studied by Tabushi. @
been
Sodium chlorlde increases the eX-
traction yield and broadens the favorable PH range.
EDTA
permits the separation of uranium from thorium and flsslon products by more effective masking of the latter.
Uranium
has also been extracted with acetylaoetone using butylacetate as solvent.=
182
1’
I
1
100
[
1
U(lv)
1
I
I
I
1
I
I
I
I
I
I
PIJ(lv)
80 o
Hf(lV)
U(W)
:
i
eo ■
n 40
Th(lv)
l?o
~
:,,,,!
o -101
234867891011 EQUILIBRIUM
121314 PH
Figure 54-A. The extraction of varlouB elementO from O.1~ NaC104 solutions by an equal volume of acetylacetone-chloroform solutlon at 250c. Acet lacetone cone ntrationE used: U(VI), O.O21OM 5 [1-IAa aq; U(171 7 , 0.50M [HAa] erg; Pu(IV), 1.00M [HAa]lnlt;~h(IV), 0.04 b 9M [HAa]lnit- q) IV , 0.050~ [EL4a]oorg. ~ter J. Ftydberg, referefices 51, 488-48 .
I00
1“’’’’’’’’”1
eo 60 11
n 40
20
0
-1
0
I
234567891011 EQUILIBRIUM
PH
Figure 54-B. The extraction of various elements from O.1~ NaC104 aolutlone by an equal volume of acetylacetone-benzene solution at 250c . Acetylacetone Concentration uBed: U(VI), O.O21OM [HAa]aq; u(IV) 0.072M [HAa]aq; Pu(~), 1.00M [HAa]lnlt; Th(IV), u.0673M [HAa]~org; ~.,0.70M [HAa]oorg. fiP. Irradlatlon time = coolti time = 1 year. AfteF J. Rydberg, re~erences 51, 487, 488, 492 and J. Rydberg and B.”Rydberg, reference 14b.
183
I
I
I
1
I
1
I
I
I
I
I
I
I
I
[
I
I 1 121314
100
Pu(lv) 00
U(vl)
A
60 /
;T
40 20 0
1 1 -101
I
I 234567
e91011
EQUILIBRIUM
PH
The extraction of various elements from O.lM NaC104 Figure 54-C. solutlons by an equal volume of acetylacetone-hexone solu’lon at 250C . Acetylacetone concentrations used; U(VI), 0.0210~[HAa]aq; Pu(IV), 1.00M [HAa]inl’t; Hf, 0.050M — [HAa]Oorg. After J.-Rydberg, references 5~, 487, 488.
o
0
Benzoy.lacetone, g - ; -CH#-CH3. Stax~~
haa determined the stablllty oonstants of
uranyl acetate, oxalate~ tartrate, and EDTA complexes.
The
effect of these Ions was observed on the extraction of’uranium (VI) from 0.1~NaC104
solutions by O.~benzoylacetone
in
benzene. .
2-Acetoacetylpyr Idine,
(’J-:
o
0 - c%
-:
- CH3.
The extraction of uranium from a 0.2~ NaOH, 0.2~ acetic acid solution at PH 5.0 in butylacetate
to 6.5 by O.l@
acetoacetylp~ldlne
Is reported by Hera.%
o
n
Dlbenzoyl,methsne,
v - C -
0 cl-$- ; - ~.
Uranium (VI) (0.05 - 0.5 mg) Is extracted from aqueous solution by a 0.5~ solution of dlbenzoylmethane In ethyl acetate.=
In the presence of other catj.ens, the extraction is
made more seleatlve by the addition of complexomIII sodium salt).
Excess complexomls
184
(EDTA
ao~plexed by a l% Ca(N03)2
I
I
1
i
I
I
I
I
I
I
I
I
I
I
I
I
I
I00 0
80
!
CIJ$
60
40
—Originally aqueaus
in layer
in ---Originally acetylacetate
20 I 0 -1
0
I
234567691011
121314
EQUILIBRIUM
PH
Figure 55-A. The extraction of various metals from aqueous solution by an equal volume of acetylacetone at 250C. Solid lines indicate the metal was ortglnally contained in the aqueous phase. The dashed lines indicate the metal was originally In the organic pha6e. The pH was adjusted to the desired value b$~’furlc acid or .90dium~droxlde. F&ter A. Krlshen, reference
I00
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0 ##.
o w
u,/;
H
60
--
EDTA //
60
—Metal:EDTA=
; h
1-
40
Z
a w
n
: ef
5’ :
20
L
1:30
--Metal: EDTA= 1:10 . . . . . . Metal : EDTA s I :15
‘f n
/ ; I I
#’&l
Ofl
&’0
1 -1
I 0
I
2
3
4
5
6
EQUILIBRIUM
7
6
9
1011
121314
PH
Figure 55-B. The ef?ect of ethylenedlamlnetetraacetate (EDTA) on the extraction of various metals from aqueous solution by an equal volume of acetylacetone at 250C. The mole ratio of metal to EDTA Is shown by the line texture. Mter A. Krishen, reference 489.
185
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I
I
1
I
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I 1
80 60 40
20
#
o
!1111111
1111111111 -1012345678
91011121314 EQUILIBRIUM
PH
Figure 55-C. The effect of fluorlde on the extraction of various metals from aqueoua solution by an equal volume of acetylacetone at 250C . The mole ratio of metal to fluoride Is shown by the llne texture, After A. Krlshen, reference 489.
1
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â&#x20AC;&#x201D; Metol : Tortrote =1:30 _ _ _ ~~tol :To,?rot, =1:10
81 #l
1 1
-101
2
3
4
5
e
EQUILIBRIUM
7
e
9
IO
II
121314
pH
Figure 55-D. The effect of tartrate on the extraction of various metals from aqueous solutlon by an equal volume of acetylacetone at 250C . The mole ratio of metal to tartrate Is shown by the llne texture . After A. Krishen, reference 489.
186
solution.
The reeultlng solution Is neutralized with ammonia
to pH 7 and Is then contacted several times with the extractIng Oolution. The dibenzoylmethane
extraction of uranium with chloroform,
benzene, and carbon tetrachloride has been investigated by A l@ Moucka and Stary.—
l!henoyltrifluoroacetone (’ITA) 9
-c lot s“
-C~-C-CF~. n o 0
Considerable effort has been expended In the study of TTA as an extractant for uranium. and Crandall,~
Klng,~Orr,~ 500 Walton, et al.,— and Peterso~
Heielg have
made fundamental studies on the extraotlon of uranium from aqueous perchlorat-
and nitratw
media by
!l?TAdlasolved in benzen~ 497’ 498,~o0,Ljol hexone,~ hexanone,~
and pentaether.—499
(VI)
cyclo-
The psrtitlon coefficient,
‘u(VI )J is increased by Increased TTA concentration In the organic phase; decreased by increased initial uranium concentratlon.~
The effect of pH and various salting agents
on the extraction of uranium (VI) and thorium from nitrate solutlons by 0.2~ TTA in benzene is shown in figure 56.= SaltLng agents increase the extraction of uranium by TTAbenzene from low pH solutlons.
There
is no apparent effect
on the extraction of thorium with or without lx A1(N03)3. A 4N .NH4N03 concentration In the aqueous phase (not shown), in fact, depresses the extraction of thorium.~ of foreign anions on the extraction of U(VI)~
The effect and U(IV)~
from aqueous perchlorate solutlons by 0.5~ TTA in benzene is shown in figures 5W and Forema~
and 57*, respectively.
Poskanzer
have recently reviewed the extraction of
elements throughout the periodic table by TTA.
The pHvalues
50 percent extraction into an equal volume of 0.2~ TTA in benzene at room teIpperature or 25”c. llsted by these authors 187
for
100
80
60
40
20
0 -1
0-
I
2343 p“H
Figure 56. The effect of PH and Baltlng-out agenta on the extraction of uranium (VI) and thorium by !l?PA-benzenesolutions. After E. K. Hyde and J. Tolmach, reference 502. Condltlons: An equal volume of 0.2M TTA In benzene was stirred vigorously for 20 minutes with an aqu~ous solution containing 0.003~ thortum or trace amounts of uranium-233 with or without the Ealtlng-out agent Indicated at the pH given.
are: for U(VI) from dilute nitric acid,=
pH50 = 1.97;
i’orU(VI) from HC104 + LIC104,~P=2, PH50= 1.79; for 14a = -0.58; for u(rv) U(IV) from HC104 + NaC104,— ~ = 2’ PH50 from HN03,~
p~o
= -0.31.
Irving and Edglngto@
have observed a synergistic en-
hancement of the uranium partition coefficient with trlbutylphosphate (TBP) - or trlbutylphosphlne oxide (TBPO) - !l?PA mtitures.
The results, ~
versus percent TBP or TBPO In the
extractant mixture, are g%ven in figure 58. The analysl.s.of metals with ‘ITAhas been reviewed by Moore,~Sheperd
and Melnk~
have publishe~with
references,
the extraction cnwves of a large number of elements with !!TPA. 188
“
U(vl)
1.0
au
o. I
0
1
n
i
I
I
I
1
I
I
2
3
4
5
6
7
$’9
NORMALITY
CONIPLEXING
1 10
AGENT
Figwe 57-A. The effect of’foreign anfons on the extraction of Wter uranium (VI) from aqueous perchlorate solution by TTA-benzene. R. A. Day, Jr. and R. M. Powers, reference 77. Conditions: Organic phase - 0.50~ TTA In benzene pre-treated by shaking with dilute perchlorlc acid overnight. Aqueous “phase - -10-SM U2ss, anion at concentration Indicated, 0.05M HC104, plus sufflc~ent NaCIOq to maintain an ionic 6trength of 2.O. ‘Equal phase volumes shaken together for 2 hours at 250c.–
1.0
au
Figure 57-B. The effect of ~orelgn anions on the extraction of uranium (IV) f’rom aqueous perchlorate solution by ‘lICA-benzene. After R. A. Day, Jr., R. N. Wllhite, F. Do Hamilton, reference 58. Conditlone: Organic phase - O.O5M TTA In benzene pre-treated with dilute acld.– Aqueous phase - 0.0016M - 0.0037M U(IV), anion at concentration indlca~ed, l.000~ ~ (HC104 used for all experiments except chlo~ ride in which HC1 was used), plus sufficient NaC104 to maintain an Ionic stre~th of 2.0. Equal phase volumes shaken together for 30 minutes.
0.1
0.01
0!23 NORMALITY COMPIEXING AGENT
189
,03 I
1
-
P——
TTA-TBPO
1
I
I
J
--’%@
1
e
!02 \@
1.0 1
k
0
I
0
!
1
I
I
I
I
10 20 30 40
50
60
%
TBP
I
I
I
7’0 80
90
I
100
OR TEIPO
Figure S8. The synergistic enhancement of the uranium (VI) partl tlon coefficient between aqueous nitrate solutlona and mixtures of TTA and TBP or TBPO In cyclohexane. After H. Irving, D. N. Edgington, reference 451. Conditions: Organic phase - 0.02M mixture -1-025 x 10-~i TTA and TBP or TBPO In cyclohexane. ual phase volumeE shaken together for 24 hou~a Z3Z;o;”;;&=2&e~210-230C.) ‘queOu”phOe “
190
Sub6tltuted l-phenyl-3-methyl-b-acyl-pyrazoloneB-5~ ~ CH-C-CH-C=O 3
“1 ‘\/c = 0 ~6H5
Skytte Jense@haO
stiudled the posalblllty of using
substituted l-phenyl-3-methyl-4-acyl-pYrazolones-5
as extrac-
tants for a number of elements Including uranium (VI), thorium, and lanthanum.
The pH for 5C@ extraction of trace amounts of
these elements by a 1~ solution of chelating agent In chloroform Is given In Table lCKXII. The PH50 for !lTTAis given for comparison.
4~~ (8-hydroxyqulnollne, oxlne “>; ~m l+’?~ ..
84ulnollnol
.
and Dyrssen and Dshlberg—143 have 6tudied the ex-
H~k,~
traction of uranium (VI) from aqueous perchlorate solutlons by oxlne dissolved In chloroform or hexone.
Results of the 143 latter group,— percent extracted versus final aqueous pH,
are shown In figure 59. those of H~&~
These results are In agreement with
(0.1~ oxine - CHC13, 10-~
chlorate solution, v = o.1~, 25”c.).
U; aqueous per-
No appreciable differ-
ence was observed with uranium concentrations of 10-4~ (open and solid circles, respectively,
10-%_
in figure E@). Chloro-
form IS shown to be a slightly better solvent for the uranyloxine complex than hexone. La and S= pH for 5@
508 The extraction curves for Th,—
are also shown in the figure.
A tabulation of
extraction of various metal oxlnates by chloro-
form has been made by Dyrssen and Dahlberg~
and is repro-
duced in Table ~111. The extraction of uranium (VI) by solution~ of l? oxine In chloroform from buffered aqueous solutions 1s shown In
510 figure 60 as a function of aqueous pH.— 191
Table XXKII. ~orium,
pH for 5@
Extraction of Tracer AmountE of Uranium (VI),
and Lanthanum by ~
methyl-4-aayl-pyrazolonea-5
Solutiona of Substituted
(R) l-Phenyl-3-
in Chloroform.~
~
PH500f
Metal Ion
Thw acetyl
-0.15
0.10
2.60
proplonyl
0.05
0.05
2.65
klutyryl
0.52
0.42
2.47
valleryl
0.24
0.24
2.84
capronyl
0.7
-0.25
3.15
ethoxycarbonyl
1.00
not mess.
2.50
chloroacetyl
0.65
tri.fluoracetyl
008
not mess.
benzoyl
1.0
0.4
2.4s
p-bromobenzoyl
0.9
0.30
2.3
0.05
2.28 not mess.
p-nltrobenzoyl TTA
0.70
-0.30
3.75
Values for pH50 were calculated from data presented by B. Skytte Jensen, reference 16o. Aqueous perchlorate media.
192
I00
80
s
1 U(vl)-ck
/ R
U(Vl)-he]
60
40
8
1
20 [ 1
0
-1
0
I
Q
34
5
6
I
1
1J
7S9!01112131415
EQUILIBRIUM
PH
Figure 59. The extraction of traoer amounts of uranium (VI), thorlun, samarium, and lanthanum from perchlorate solution by solutlons or oxlne-chloroform or oxlne-hexone. After D. Dyrasen-and V. Dahlberg, referenoe 143J D. Dyrseen, references 508 and 509. Conditions: Aque ous phase - Ionic strength = O.lM with NaOH, HC104, and NaCIOA; for uranium, open circles represent b.0001y U concentrations, solid circles and triangles, 0.00IM U. Organic phase - oxlne concentrations: for U, O.100&; for Th, 0.050~; for La and Sm, 0.5~; solvent, indicated. Equal phase volumes equilibrated at 25°C.
Subati.tuted qulnollnola. Rulfs, et al=
and Dyrssen, et al.~have
studied the
extr.aotlon of uranium by di,halogen .derivatlvea of &qu3noIIno.1,
The ursnlum extraction curves wl~h 1$%aolutlona of
5,7-dichloro- and 5,7-dibromo-8-quinoltnol
in
chloroform
are 8hown aflfunctions of final aqueous pH in figure 60.U Use of the halogen-subgtltuted
oxtnes permits extraction .of
ursnlum from more actdlc aqueous solutions.
‘Similar ourves
for uranium, thorium, and lanthanum are given in figure 61 for extraction with 0.05kJ 5,7-dichloro-oxtne Hyne~has
in chloroform. ~
studied the extraction of various ❑etalm
by 8-hydroxyqulnaldine
(2-methyl-&quinolinol).
The ur~im
complex was found to be extracted, but n&quantitatively~ 193
‘
Table XXXIII. pH for 5*
Extraction of Metal Oxinates. with Chloroform.~ Reference
Metal ion
pH
Procedure
~a3+
1.0
V aq = V erg, O.~_ total oxine.
~n3+
2.1
Anions In aqueoua solution: chloride.
~3+
3.4
~e3+
1.6
~2+
2.0
Four auocet!Blve extractlona with O.0~ solution of axlne In CHC13a
#+
2.2
Anions In aqueoua solution: sulfate,
B~3+
3.0
acetate, nitrate, chloride.
A~3+ ~i2+
4.2 6.1
~02+
6.5
Sn%
0.0
Vaq=
MO ~e3+
1.0 2.0
Antont3 In aqueous aolutlon:
Cu
2.1
NI
3.7 3.8
Al ~2+
5V erg,
512
513
OoOi’goxtneo
acetate, chlorlde~ tartrate.
6.4
Hf%
1.3*
V aq = V erg, O.1~ total oxlne.
U@+ T@
2.6
Anions In aqueoua solution:
3.1
perchlorate.
s> =3+
5.7 6.5
SAfter
511
143
D. Dgraaen and V. Dahlberg, reference 143.
●~=-log[H+]
+0.1.
by chloroform from an aqueoua phaae at PH 9.5 containing tartrate and acetate Ions.
Cyanide or ~02
prevented ex-
traction. N=O ~ /)
l-Nitroao-2-naphthol ‘d Alimarin and Zoloto~
\
-OH
.
have Investigated the extraction
of uranium (VI) by organic solutions of l-nltroso-2-naphthol. It waa found that a mole ratio of naphthol to U308 Of 125
194
Dichlo
Dibrorno
The extraction of uranium (VI) by oxlne and its 5,7 +iichloroand 5S7-dlbronm-derivativea. “mlculated
~om
The percent extracted, P, was
the values of the distrtbutlon coefficient
given in the paper by C. L. RuMeS
A. K. De, Jr., J. Lalu?ltz,
and,P. J. Elvlng, referenoe 510. Conditions: 2.1 mg of uranium In 10 ml and 25 nilof an approximately M buffer solution were Shaken 6 to 8 minutes with 20 ml 03?a 1S oxlne-chloroform polution. The aqueous phase was rinsed twiue wtth 5 ml of chloroform. ‘lTiePH of’the fhal aqueoua phmie wa6 meaeured.
195
!-
(
<u(w) .
/La
.
20
0
.
-1
0
23456789!0
1
EQUILIBRIUM
PH
Figure 61. The extraction of traoer amounts of U (VI), ‘I’h,end La by 0.05~ 5,7-dichloro+xine from O.~
dls~olved in chloroform
HC104 - NaC104 solutlons at 25°C.
After D. Dyrat3en, M. Dyraaen, and E. Johanaaon, referenoe 514.
and a volume phase ratio of orgardo to aqueous of
0.25 h
more than adequate to give quantitative extraction of uranium Into Isoamyl aloohol at a PH of 5 to 6.
TWO minute shaking
IS sufficient for quamtltatlve uranium extraction.
Ethyl
acetate, n-butanol, dlethyl ether, aEWl aoetate~ benzene, and chloroform also extraat the uranium-naphthdlAte complex. Quantltatlve extraction is obtained with ethyl acetate and n-
butanol at a pH of 3.0 to 8.5; with Isoamyl aloohol at pH 4.5 to 7.5.
Quantltatlve extraatlon c!anbe ati,ieved at tem-
peratures of O“ to ioo”c.
Chlorlde or nttrate Ions at con196
centrationB up to 0.2y do not serloualy Interfere with the extraction of uranium.
Iron (III) is completely extracted;
vanadium (IV) and (V) and thorium are partially extracted. The extraction of all four metal ions Is considerably suppressed by completing with complexo~III
(sodium salt
The pH range for quantitative separatlonof
of EDTA).
u-
mantus with isoamyl alaohol is Increased In the presence of COmpleXOmIII
(-25 mg complexomper
Aluminum and zinc
mg of metal) to 6,5 - 9.
not extracted with l-nitroso-2-naphthol.
are
studied the extraction of uranium
Dy77s8en, et al.~have
and thorium from squeous perchlorate solutlons (P = O.l@ by O.1~ l-nitroso-2-naphthol
In chloroform.
Fifty percent
of the uranium was extracted at pH 3.07 and fifty percent of,the thorium at pH 1.66. extracted.
Lanthanum and samartum were not
Other metals that have been extracted as nitroso-
naphtholates include Mn(II), Fe(II), Co, Nl, CU(II), Pd(II), Ag, Cd, Hg(II), Pu(IV)~and
Np(V).~
Ammonium salt N-nltrosophenylhydro~lamine
:1~: o
:-ml )
(cupferron),
.
Cupferron is an important reagent in the analytical separation of uranium.
The reagent precipitates uranium
(IN) from acidic (H#04
or HC1) solution but not uranium
(VI).
By converting
uranium to Its two oxidation states,
separation csn be made alternatively from elements not precipitated by cupferron and from those precipitated by the reagent.
The uranium (IV) cupferrate COmPleX, U(CUP)!,
was found by Auge= organic solvents. of uranium
to be soluble in chloroform and neutml Furman, et al.=
found milligram mounts
(IV) to be incompletely extracted from aqueous
acid solution by hydrogen cupferrate in chloroform but to be almst
completely extrccted by ethereal hydrogen cup-
197
ferrate; I.e., cupferron extracted by ether from an aoid solution.
Ethereal hydrogen aupferrate wae elBo found to
extraot quan$ltatlvely macroamounts of uranium {IY) from (1+
19) sulfurlo aoid oontainlng hydroxylamine hydrochloride
and submillZgram anmunts from (1 + 19) sulfuric auld In the presenoe of saturated mrcury-zinc coefficients ~(~)s
~gam.
*
The partition
1s Inoreaeed with Inareaaed oupferrate
concentration and Is deoreased
with increased aoid ooncen-
.“
tratlon.~ A uranium (VI) cupferrate oo~lex the reagent from neutral eolutlons.
16 preoipltated by There appear to be two
forms, one of’whioh Is soluble In ethyl ether. ~ (1+9)
mom
sulfurio acid, milligram amounts of uranium (VI)
are extracted by an equti volume of chloroform with an exoeOs of’ oupferron present.
~
The extraction of uranium (VI) oupferrate from perchlorate solutlon by hexone
aqueoua
end chloroform lE given in
fl&ure 62 as a function of the pH of the final aqueoua solutlon.~
Chloroform Is a poor solvent for
the complex.
Hexone 18 better, but quantitative extraction IB not aohleved by a single oontaot of the solvent with an equal Volulm of’ the aqueous solutlon. and *
The extraction ourves for
m,=ml,
are alao given In the figure.
The properties of other metal cupfematem
have been
reviewed by Furman, Mason, end Pekola.m
N-Benzoylphenylhydr “tine”
e;””
eN-OH” D’grsee~
has studied the extraction of uranium (VI)
with N-benzoylphenylhydroxylamlne perchlorate solutions.
in chloroform from aqueous
The results, P versus pli, are Bhown
in figure 63 together with thoee for thorium and lanthanum.
198
I 00
60 P
40
20
I
0
0
-1
1
234567
e91011
EQUILIBRIUM
1213
PH
Figure 62. The extraction of tracer amunts
of uranium (VI], thorium,
samarium, and lanthanum cupferrates from perchlorate SOIU. tlons by hexone or chloroform. After D. Dyrssen and V. Dahlberg, referenae 143; D. Dyrssen, references 508 and 509. Conditions: Aqueous phase - ionfa strength = O.lM with NaOH, HC1O amd NaC104. Na cupferrate added to aqiieous phase: for 8, O.OIMM for Th, Sm, and K, 0.005P& Equal volumes of aqueous and organtc Bolvent Lndlcated equilibrated at 25”C.
l-(2-Pyr ldylazo)-2-naphthol
(PAN)g 0-”=:s
l-(2-Pgrtdylazo)-2-naphthol
●
forma colored complexes
(generally red) with a lazge number of polyvalent metal ion~.~
me
uranyl-pw
COmpleX ISIinsoluble In alcoho18,
carbon tetrachloride, chloroform, and ethers.—522
199
Ortho-
01
EQUILIBRIUM F@ure
pf+
63.
The extractldn of tracer qnmunts of uranium (VI), thorium, end lanthamui from perohlorate solutions by N-benzoylphenylhydro~lemine
dissolved In chloroform.
After D. Dyrasen, referenoe 520.
CondltionO: Aqueous phase - Ionlu strength = O.lM with HC104, NaOH, and NaC104. The aqueouE phase waa so--times buffered with 1 ml of O.~ anllinium perahlorate, sodium acetate, or hydrozinium perohlorate per 15 ml. Organlo phase - O.~ N-benzoylphenylhydroxylamine in chloroform. Temperature, 25째C.
or meta-diohlorobenzene Vd29
for the complex.
and brcnmbenzene me
exaellent sol-
The maximum aolor of the uranyl-PAN
aomplex is developed at pH 10.
At pH lesB than 5 or greater
than 12 ltttle aomplex formation ooaura.~
Uranium may be
selectively separated from a lerge number of elements by PAN-diahlorobenzene
extraction in the presence of masking 200
agents (EDTA, trlnitrilotriacetlc
acid, cyanide) and with
proper pH control. & Sodium dlethyldithlocarbomate Bod~
5
(DDTC), (C2H5)2N -C=e-Na+.
reports that the U(VI) - DDTC complex,aunlike
other heavy metals$ is tsoluble In water.
A precipitate lb
formed only with high concentrations of uranium and reagent. The uranyl-DDTC oomplex Is practically inextractable by carbon tetrachlortde but Is readll.y extracted by isoamyl 523 alcohol, diethyl ethers and a?qylacetate.— used hexone,~
ethyl acetate, ~
zen~to~traot
theco~l-.
Others have
chloroform,=
and ben-
Employing the above sol-
ventss the U(VI)-DDTC complex has been extracted from aqueous solutions having a wide rsnge of pH, e.g., pH 1- and pH 6.5-8.3.=
Sodium tartrate has been used to prevent
hydrolysis at higher pH values.~
The U(VI)-DDTC complex
Is extracted in the presence of EDTA.
Uranium may then be
separated from element% such as thorium,that form strong EDTA complexes.~
24,527,528
Uranium may be further separated from
those elements extracted as DDTC complexes by strlpplng the cerbonate solutlon. 196,525
former Into an ammnlum
CH=N-C~C~-N=CH-
I \-oH
Disalicylethylenedlimine Dyr6se~
@ reports thatiuranium (VI) Is so~~what
extractable (60-9@) dilmine
o k
with solutions of dlsalicylethylene-
In chloroform.
(90-99%) f~mweulY
Hsfnlum and thorium are extracted
acidic solutions (PH1.5)
0.5g chloroform solution of the reagent. samarium are not extracted. Antlpyr tne,
CH = I
O=c
1“
- CH3 7
N - CH
y’
I c6H5
201
3
with aO.l-
Lanthanum and
Ro~de@
has mentioned that ohlorofâ&#x20AC;&#x2122;orm extracts uranyl
complexes with antlpyrlne.
Rea~
has reperted that both
uranium (VI) and uranium (IV) are almost completely extracted with antlpyrlne-chloroform
solutlona from perchlorate media.
Uranium may be separated from thorium u~lng the antlwlnechloroform system.
Rrom an aqueous solution of 20.6 ml
containing 5 nmd-of 48.6 mmdes
Th(N03)4, 1 mle
of U02(N03)2 ~d
of HC1, 93-9%% of the uranium and only 5$ of
the thorium was found to extract with 36 moles rine In chloroform.
The uranyl-antlpyrlne
of antlpy-
oomplex iH
soluble in nltrobenzene, but not very soluble in hexone. /.\. \ {> 7 OH
Tropolone$
+0
The extraction of U(VI) and Th from O.~
perchlorate
solutions by O.O~_ tropolone in chloroform 1s given function of PH in figure 64.=
as a
The pH of 5c@ extraction
for U(VI), Th, and Y under the above conditions Is approximately 0.9, 1.1, and 4.0, reepectlvely.
L12SS than 507
lanthanum is extracted at pH 6.5.= l)yrsse~
reports the extraction of auranlum
(VI)-
beta-isopropyl tropdlone complex with chloroform and hexone.
A number of articles are available In
Ion Exohange., which the bhavior
of ursni.um toward ion exchange resins
Is reviewed and In whtoh reference to muoh of the literature IS given. Palel,~
Hyde,â&#x20AC;&#x201D;339 ~tz
-d
and Kuznetsov, et al.=
Seaborg,~ ChoPPin, m have reviewed the ion
exchange of a number of the aatlnlde elements Inoluding uranlunh
Steele -d
Taverne~
h@ve outllned several
anion exchange separations of uranium.
Clegg and Fole#~
have deaoribed the use of ton exchange resins in the processing of uranium ores.
202
I
I
I
1
I
I
I
I
I
I
1
1
1
I
1
I
I
I
1
I 1 121314
I
I00
E!o %’ -4
u (W)
~Th
60
II 0.
0
40
20
I -1
0
I 0
1 I
1“ I I I 1 234567891011 PH Figure 64.
The extraction of trace amounts of uranium (VI) and thorium from O.~ form at
perchlorate solutlon by 0.05~ tropolone In chloro-
25”c.
After D. Dyraaen, reference 53o.
In the following psr~aphs,
the dtBtribution of
uranium (and of’other elements) between an ion exahange resin and a particulsx solution is described in terms of the clistr~butlon coefficient~, D and Dv.
These are defined
aa = . amount @x/gram
dry reOin
emount M+X/ml solution and D . amount M+X/ml reein bed v amount &x/ml solution
.
The two coef’flcient6 are related by the denBity of the resin bed, Dv = pD. ~
by many authors.
The coefficient D is referred to as
Anion exchange. .-,.--—-------
AnIon exchange reBina oommonly used
In the radlochemical laboratory are the strong baae
resins
such as Dowex.1 and-l?and Amberllte IRA-41O and IHA-400. me
capacity of theBe reOlns 1s .approxlmately 2.5 mllll-
equlvalents per gram of resin. available.
Weak base reslna are also
However, their uOe 16 more limited.
These
re6in& have capacities ranging from about 6 to 10 mllliequlvslentfl per gram of resin. Spivey , et
al.=
Investigated various factors
have
such as resin capacity, resin phase volume anion adsorption, etc~ tihattifect the sorption of uranium.
!l’rlvieonn~
has made a literature 8urvey of factors that Influenoe the adsorption and elutlon of uranium by and from strong base anion exahange resins.
These are similar to the factor8
influencing solvent extraction and include, other than thoge already mentioned, uranium concentration, anion ccmcentratlon, PH, the presence of other metalllc tons and foretgn anions$ temperature, re81n size, porosity, crosslinkage, etc. The various
systems from which uranium may be adsorbed
by anion exchange resins are described below.
The reeln
may be converted to a partl.culsr anionic form by washing with an appropriate solutlon. Chloride systems. Krau6 and Nelso @havemeasured
the dletribution
coefficl’ents for a number of elements betweem a strong base anion exchange resin (Dowex-1, l@
DVB, -200 mesh) end
hydrochloric acid solutions of varying cmlsrity. re~ults are shown in figure 65.
!l!helr
The reeults of Marcus, ZK
obtained under conditions similar to those used by Kraus and Nelson,%
are given in figure 66.
The concentrations
of the various elements used In the study by Marcus were such that the oxldatl.on atatea could be determined spectro-
204
Be
Fxi! 003. NOA o
K&H 0
NOA
AD&
NO A03, -NO EL. ADS. -8
ADSORPTION Ll~HT
althj
ADSORPTION
HCI .12 IN l!3Ej
HCI
(1234DGI) STR. AOS. - STRONG
A060RPTION
Dv=l
â&#x20AC;&#x2DC;s ul
Figure 65. Adsorption of elements from hydrochloric acid solutlon with anion exchange resin (quaternary amine polystyrene divinyl benzene resin, -200 mesh, 1~ DVB). After K. A, Kraus and F. Nelson, reference 536.
100
10
*J
~
o12345e7â&#x20AC;&#x2122;e HCI CONCENTRATION,
M,
Figure 66. Adsorption of elementO from hydrochlorlo acid solution with Dowex-1 anion exchange reBin (l@ After Y. ~cua,
referenue 5Y.
206
DVB).
photometrically. was found.
No adsorption of Np(V), Pu(III), or Am(III)
The data
presented by Wial@
for the adsorption
of’various elements by Dowex-2 { x8j200-400 mesh) is represented in ftgure 67.
Ward and Welc~have
studied the
distribution of neptunium In various o%tdatlon ~tates between Amberlite IRA-400 and hydrochloric acid Bolutlons varying concentration. strongly adsorbed at adsorbed from ~
of’
Their results show that Np(VI) Is >6~ HC1,
Np(V) is exponentially
to 6M HC1 (D increases from 1 to 10), and
Np(IV) ts similarly adsorbed from about 6~ to 10~HCl 540 Prevot, et al.—
Increases from about 2 to 400).
(D ~ve
Investigated the adsorption of U, Pu, !i’h, Fe, Ce,and Zr by anion exohange resin A300D from hydrochloric acid solutions ranging In molartty from
4 to 7.
Quenttti.es of 7 mg
PU,.6.9 mg U and 5.9 mg Fe per ml of solution and 2 grems of resin were used in the determination of D.
Their results
are considerably different than those shown in figures 65-67. The distribution coeff’iclents of U(VI), and Fe(III) are lower roughly by an order of magnitude.
The dlstrtbutlon coefflaient For Pu(IIIj,
of Pu(IV) IS almost an order of magnitude higher. D IS about 0.1 at 4~HCl
and about 1 at 7~HC1.
Zirconium
adsorption is stillar to that shown in the figures.
Thorium
and oerlum are poorly or not at all adsorbed. Korklsch, et al.-ha~e
found the distribution
coefficient of uranium between Dowex-1 and hydrochloric aald solutlons to increase with Inareased elcohol concentration of the solutlon.
With 8@
etihanol~ D Is increased from about
40 to 6000 as the HC1 concentration is increased from 0.2~ to 2.4~.~
The distribution coefficient at 2.4~ HOl without
alcohol Is about 40.
Alcohol also Inareasea the adsorption
of thorium, titanium, and zirconium.
The dlstrlbuttan oo-
* 95$ alcohol denatured with benzene Is considered 10C@ alcohol.
207
,~4
,&
t
I 02
10’
!.0
I o-’
0--
14 HCI
CONCENTRATION,
&l
Figure 67. AdoorptZon of elements from hydrochloric acid solution with Dowex-2 anion exchange resin (x8, 200-400 mesh). After L. W@h,
referenae 538.
208
efflclents of these elements vary roughly between 1 and 10 from &@
alcohol solutions contalntng HC1 in the range of
Numerous Reparations of uranium from other element6 are poselble ustng hydrochloric sold systems.
The more ob-
vious ones are tho~e In which uranium Is adsorbed snd the other element Is not.
Consideration of figure 65P Indloates
that uranium can be eeparated from klkali metals, alkallne earths, aluminums yttrium, rare earth6, actinlw~
and thorium
by adsorption as ursmium (VI) on a strong base anion exchange resin from a concentrated hydrochloric acid solution. Trivalent actlnlde elements are not adsorbed from hydroohlorlc acid solutions.
Plutonlum Is eluted as Pu (III) with
12~ Hcl oontatning hydroxglamtne hydrochloride and m41, NH41 alone, or HI.
Separations may be made by adsorption of
the contaminating element and elution of uranium with dilute hydrochloric acid. O..~HCl.~ Hc~~544,545
For example, molybdenum Is adsorbed from
Bismuth is also adsorbed from dilute (~~) Other elementB that show strong adsorption from
dilute HCl Include many of the transition metals, tin, tellurium, and polonium.~
Kraus and Moor~have
effected
the separation of protaatlnlum and uranium by adsorbing them from 8~ HCI on a column of Dowex A-1 resin snd developing the column with 3.8E HC1.
Protactinium appeared first In
tk,e eluent, separated from uranium. contained
The uranium fraction
however~ a fâ&#x20AC;&#x2122;atr emount of protactinium
~talltngj .
Advantage may be taken of the different dlstrlbutlon ooefficlents exhlblted by ions In various oxidation Btates to effect their separation from uranium. ferrous Ion by hydrogen iodtd~ Beparated by elutlon with 4! HC1. from Pa(IV) and Th(IV).
Iron reduoed to
or ascorbic aol&J@
Ie
U(IV) may be separated
U(lX) Is adsorbed by Amberllte
HIA-401 (100 mesh) and Dowex-1 (100-200 mesh) from ~~
209
HC1.
Neither Pa(m)
nor
Th(IV) 16 adsorbed from 6~ - 12.65 HC1.~
The elutlon of Pu(III) by 12~ HC1 from strong base anion exchange resin has already been mentioned. have effeoted the separation
of’Th, Pu, Zr, and Np from U
by elution with hydrochlorto acid
in a sequence of ooncen-
The elements are adsorbed on the resin (Dowex-2)
tratlonso from 12~
Wish and Rowell~
HCI.
Thorium does not adsorb=
Plutonium is eluted
In the trivalent titatewith 12B_9 HC1 saturated with hydroxylamine hydrochloride and emmontum iodide.
Zirconium Is eluted
with 7.5g HC1; neptunium (IV) with a 6g HC1 - 57 ~OH solutlon.
Uranium Is finally eluted with O.1~ HC1.
Korlclsch, et al.~have
separated uranium from tung-
eten by means of anion exchange. on Dowex~ 8@
“ HC1
The uranium Is adsorbed
resin from a solutlon containing 2W
ethanol (volumeX).
any iron pre~ento
41 HCI and
AOaorbio acid Is used to reduoe
The resin 16 washed with a similar solu-
tion and uranium Is eluted with an ether-saturated O.1~ HC1 solutton.
No tungsten Is observed In the final
eluate.
Fluoride systems. Fari~
has reported the adsorption of elements from
hydrofluoric acid ~olut%on~ with Dowex-1 anion exchange resin (xlOj 200 meeh). 68.
His results are shown in figure
Uranium (VI) adsorption is strong from dilute I-IF
solutlons and deareases with Inoreased aoid aoncentrfntion. Separation from elements exblbiting no or strong adsorption from HF solutions may be aohieved by proper selection of the aoid concentration.
Elements such
as Be,
B, Sc, Ti, Zr, Mo,
Sn, Te, Ef’, Ta, W, Re, and Hg have adsorption curves similar In shape to that of uranium (VI). elements using an ~
Sepe&atlon from these
system should prove dlfflcult to almost
lmposslbl~ depending upon the distribution ooeffloient~ involved.
210
Li
e
EIIllI Bll ! ‘m-m
OA
.
NO A~-NO
;:
ADSORPTION
SL AOS_-SLIQHT 9TR. AOS. -STRONr3
20
No
Q
FROM
IM-24M
HF
ADSORPTION ABSORPTION:
LQ@ Ot8T, COEFF. >E
Ilifllm!wll
,0=
MOLSRITY
HF
ROMAN NUMERALS REFER IN INITIAL SOLUTION.
TO
OXIDIZATION
STATE
NO AOS
BIB!
limlimlm
Figure 68, Adsorption of elementm from hydrofluoric acid solution with Dowex-1 anion exchange resin (x1O, 200 mesh). After J. P. Faria, reference 552.
Bhat and Gokhala
have found evidence f’orthe ad-
sorption of the antonlc species UO 23 F- with Amberllte EIA-400. HC1-HF sysiems. Certain elements are efficiently separated from uranium by anion exchange when a combined HC1-HF eluting system Is used.
Such syateme have been studied by a number of work-
8,554-559 ers .33
The results of Nelson, Rush, and Krau~
are shown in figure 69.
Faris and Brody~
have examined
the distribution coefficient D of uranium as a function of HC1 oonoentration in the presence of O, 1, and 8gHF a function HC1.
of
snd as
HF ooncentratlon in the presence of O and 0.2M
The former three curves are slmllar In shape but decrease
In magnitude as the SF concentration Is increased.
The pre-
senoe of 0.2~HCl also oauses a decrease In magnitude of the D VE.[HF] curve.
However, the shapes of the O and O.~_
HCl ourves for varying HF conoentratlon are dlsslmllar for HP concentrations less than 4B& “’ Table XXXIV lists a number of separations of U from other elements using HC1-HF elutlng solutions. Nitrate sy~teme. The dlstrlbutlon of urenlum between anion exchamge resins and nitric acid solutlons haa been reported by a number of 6,540,543,550,557,5 60-562 workers.~3 The results of Buchanam and Fsri.&@
sre given In figure 70.
From the non- or only
slight adaorptlon of moat of the elements from nltrlc acid medlaj it appears that anion exchange affords an excellent means for purlfylng uranium.
Uranium Is adsorbed more strongly
from nitrate salt t!olutlons than from nltrlo acid solutions 6,557, 562,563 alone.~3 With DeAoldlte FF resin, the adsorption of uranium (VI) Is greatest from A1(NO ) solutions and de33 creases In the order Ca(N~2 > LiN03 > NH4N03.* Ethanol ‘~ Inoreases the dietrlbutlon of uranium to the resin phase. With an 8c@ alcohollo solutlon, the dlstrlbutlon coefficient
212
Table XXXIV.
Separation of Uranium from Various Elements by Anion
Exchange Using HC1-HF Eluting Solutions.~ Elementai m~ture
w,
u
U, W, Mo
W, Nb, Tl, V, Zr, U, Ta
Element eluted
Elutlnp, solution
w
7~HC1-1~
u
O.~
u w
7~HC1-l~HF
Mo
1~ HC1
Reference
I@
555
HC1
0.5~ HC1
W, Ti, V, 2P
555
7~ HC1-4~ HF
559
7~ HC1-O.2~ HP
m u
1~ HC1-4~HF
Ta
24~ HF or 4~ NH4Cl1~ NH4F
Fe(III)
1~ HF-O.Ol~HCl
u
~
R.E. as Eu(III),U(IV),
R.E.
8~ HC1
U(VI), Zn(II)
U(rv)
8~ HC1-O.1~ HF
Fe(III)J U
Te(lN), U(VI)
Th(IV), Pa(V), U(VI)
U(VI)
0.5~ HC1
Zn(II)
O.OIM HC1
U(VT)
~HC1-l~(to
Te(IV)
1~ HC1
Th(IV)
10~ HC1
Pa(V)
9~
u(m)
O.lM — HC1
556
8@HF
556
554
Pa
7~ HC1-O.ll~HF
u
0.5~ HC1
Zr
12g Hcl-o.06g HF
Np
605~HC1-0.004~
Nb
6.o~ Hcl-o.06~ I-IF
538 HF
alr dry column and alcohol wash O.lg Hcl-o.061j HF u Mo, Tc
12M — HNO~
~ Dowex-1 or -2 anion exchange resin used.
213
559
HC1-l~HF
9~ HC1
Pa, U
Zr, Np, Nb, U, Mo, Tc
555
HC1
. e
EEil D#lln
m mm I
Dv=l In HCI
HC
ard HCI- I ~ H ,,
e
H
Pmmm
m
,;,,#’j\_Wm
Irl 4L Isul 4 LEGEND:
wmEliEEEl MOLARITY
HCI
Figure 69. Ad60rptlon of element6 from HCl and HC1-HF ~olutlons with’anion exchange resin. Distribution coefflcient~ in absence of H’. ~Dlatrlbutlon coefflclent6 In HC1-HF mlxture6 (usually 1~ HF except Zr(rV), Hf(IV), Nb(V), Ta(V), an: Pa(V) where ~HF = 0.5). After F. Nelson, R. M. RuOh, and K. A. Kraua, reference .
Li
m
NOA09
NO AOE
E!El IL L :4
NO Am
;3
NO A03
M
kE 6
NO AOS.
‘i’ EEil ‘004812 MOLARITY
- NO A080RPTION
9L. AOK - SLIOHT
FROM l-14N
HMO,
AOSaRPTlaN
HN~
EEIH
s NO A09
NO A03.
T
v
n
W
CT El
NO AOS
NO PD9,
NO A03.
NO B
Y
Zf
N
x
kf%l!lB!l!lll%lk
m
m 9LI
HiHHHk
B; N . m
Hf
To
6k AOS
EE!liEmE!3ElEE Fr
A
Ra
HKll
HHHHHHHHHHHHHRH Figure 70. The adeorptlon of eleraentfl from nltrlc acid Bolutlone with Dowex-1 anion exchange reEln (x1O, 200-400 meBh) . After R. F. Buchanan and J. P. FariB, reference 562.
Table Xxxv.
Separation of Uranium from Various Elements by
Anion Exohange Using Nltrlo Aold Solutions. Resin
Elemntal Mixture
Eu(III), U(VI) Dowex-1
Element Eluted
Elutlng Solutlon
Eu(III)
8g HN03
Upm)
O.*
Referenoe 557
HN03
u, Ru
Dowex-2
u
lg HH03
543
Zr, U, T%I
Dowex-2
Zr
Column developed
543
u
with 8~ KM)
Zr 3“ elutes firsts followed
Th
by U and then 91L
u, ‘m
(n”c) u, Th
u Th
Dowex-1
U, Np
560
45 HN03 ~o ~methanol-~~03
U m
q
564
SN03
Dowex-1 or U.
6g~03-ferrous
Dowex-21K
hYChQ.Zinc or aemlcarbazlde o 35g Imo3
Np !lh,R.E., trana-pu, ,Pu, U, Zr, Np
SN03
q
DeAcidite FF
Dowex-2
suli?amatc-565
●
Th, R.E., trans-pu Pu
cono.HCl-trace HNO
3
550
cono.KCl Battd with ~OH=HCl and NH41 oono.HCl(8C@)-mnc.HN03(20$)
U, Zr
12~ HN03
NP
oono. HC1 4~HCl with ~
NH20H*HC1
for uranium Is about 12 between Dowex-1 resin and 1.2~ HN03 aolutlon; for a 4@ Table XXV elements ualng
alcohollc aolutlon, D la about 7.
lists a number of BeparationO of U from other nitrate medta.
The last procedure listed in
the table may be revleed to Inolude Pa separation. Followlng the elution of U with 12~HN03,
in which a s~ll
~unt
of
Pa IS eluted, the remaining Pa is eluted.with 12~ HN03-0.~ \ HF.=
216
Sulfate systems. The recovery of uranium from sulfate liquors by exchange methods is important industrially.
=L~iOn
Laboratory-wl~e,
e number of procedure6 have been.developed for the determination of uranium that make use or the adsorbability of the anlonlc uranyl sulfate complexes.
The nature of these complexes has also
received considerable study 98,566,567 (see section on complexions)The distribution of uranium between anion exchange resins and sulfate media has been reported by a number of investigators. ~ 943,550, 557$561$5m The reeults Of BunneX, etal.~ere given in figure 71.
Strontium, yttrium, cerium~ and americium do not
show any significant adaorptlon by the resin (Dowex-2) at any acid concentration. ~The
distribution coefficient of Pu(IV)
is approximately twice that of U(VI) in the aoid range of O to lo~H&04.=
The adsorption of uranium (and thorium) from
solutions of (NH4)2S04 is similar to that from H2S04.
The
decrease in adsorption is less rapid, however, with increased atmnontum sulfate concentration than with sulfuric acid.-â&#x20AC;&#x2122; ~
The adsorption of uranium from sulfate solution exhibits
a PH depefidence (D inoreases as the PH is increased from 1 to 4) which decreases as the sulfate concentration ie decreased. ~ The distribution coeffâ&#x20AC;&#x2122;iclent of uranium between Dowex-1 resin and O to 1.2~ sulfiric acid solutions is one
to three orders of
magnitude greater from 8c@ ethanol solutions than from aqueous solutions.= A number of procedures have been developed for the separation of uranium from various elements by anion exchange In sulfate solution. These generally involve the adsorption of the uranyl complex from a sulfate solution at PH 1 to 2 from which the foreign element Is not adsorbed.
After thoroughly
wa6hing the resin bed to remove impurities, uranium is eluted with a dilute solutlon of hydrochloric, nitric, or perchloric acid.
Mixtures of elements that have been or mayâ&#x20AC;?be separated
217
M
B
I
‘8 “.JW3
m
0.1
m
I
I
1111~
I
I
I
1 [[11
1
m
I
Q I
I II
1
T
i
““”%
B.o
10
I00
Jy H@o~ Figure 71.
The adaorptlon of elements from sulfurlc acid solutlona with Dowex-2 anion exchange resin (x8, 200-400 mesh). After L. R. Bunney, N. E. Ballw, 543. 218
J. Pasoual, S. Fotl, reference
from uranium by procedures similar to the one de~cribed Inalude Am, Th;~Fe,
Al, Mg;*
alkali metals;â&#x20AC;&#x153;~zr,
Fe,,V;=
Ce,
Zn, Nl, Co, Cd, Mn, Cu, Fe,
Ce, k,
Cd, V;~BI;=
and metals contained In ores.~~~.~e
R.g.;543â&#x20AC;&#x2122;571,574
literature references
should be coneulted for exact experimental conditions. Carbonate systems. Uranium 18 recovered from carbonate leach llquore by anion exchange In industrial operations.
Ita anion exchange behavior
IS simller In carbonate eolution to that in sulfate solution. That fs, the dfstrlbutlon coefficient is decreased with Inoreased carbonate concentration.
This is Illustrated In figure 72 for
ammenlum carbonate Bolutlons. ~
A ~imllar decrease in D.ts
observed for Increased sodium carbonate concentration.= distribution coefficient IB of the solutlon.
also
The
decreased by a decrease in pH
The Increase in bicarbonate uoncentratton at
the lower PH interferes with uranium adsorption.
Other anions
such as sulfate, nitrate, and chloride may also lnter_fere with To prevent gassing
uranium adsorption from carbonate solution. with mrbon
dioxide, uranium Is eluted with salt solutlomrather
than acids. Vanadlu@
and phoephate and molybdat~
have been eeparated
from urantum in carbonate Oolutlona by anion exchange.
The lrn-
puritles are adaorbed on the resin together with uranium and eluted N&l
with a 1~
N~C03
solU%lon.
U)7~tUlU
i~ eluted wibh a 5$
solution.
Phospha te systems. The dlstrlbutlon of uranium and other elements between DowexZl anion exchange re61n and phoephorlc acid solutlonB is represented in ~igure 73.=
Marcus%
hae etudled the Dowex l-uranyl phosphate
ayatern. Hts dlstrlbutlon coefficients are lower by factors of 2 to 50
at O.1~ H3P04 ad
~
H3P04, re~pectively,~
in figure 73.
219
th~
those ehown
o
c)
0.2
0.4
0.6
CONCENTRATION
0.8 OF
CARBONATE
!.0
1.2
AMMONIUM [Ml
Figure 72. The adsorption of elements from ammonium carbonate solutions with Dowex-1 anion exchange resin (x8, 50-100 mesh). After S. Misuml, T. Taketatsu reference 575. Conditions: Amounts taken, Be* 11.7 mg (Beo ; Ce&, 7.3 mg (Ce02); Th%, 26.9 mg (Tho2); and uo2~’61.0 mg (U308 1 . 1 gram of resin and 200 ml of solution In conta?t 12-20 hours at 20°C.
220
,.6
,05
a
10
I.0
,o-l,o~
I .0
10 N.
I&
I-13P04
Figure 73* The adsorption of elements from phosphoric acid solutions with Dowex-2 anion exchange Feeln (x8, 200 mesh). After E. C. Frelli.ng, J. Pascual, end A. A. Delucohl, reference 579. â&#x20AC;&#x153;
221
Separations between uranium end the rare earths (Ce3+, Ce”),
alkaline earths (Sr2+), alkali metals (Cs+), and tellurium
are possible using Dowex 2-H #04 has been used by Wls@
The latter separation
who loaded a column of Dowex-2 resin Tellurium passed through and
from a O.1~ H3P04 solution. uranium was adsorbed.
sy~tems.
The column was then converted to the
chloride form with concentrated hydrochloric acid and uranium was eluted with O.1~ HC1 - 0.06g
HF.
An alternative method
Involved loadlng the column from concentrated HC1.
Tellurium
was eluted with l.0~ H3P04 after washing the column with an alcoholic phosphoric solution.
The column
an alcohollc HC1 gas solution.
Uranium was eluted with a O.1~
HC1 - 0.06~HF
was then washed with
solution and molybdenum with 12~HN03.
MlscellaneouB systems. Uranyl tdn forms “a anlonlc complex with acetate Ions at The complex
pH 4.25 to 5.25.
has
been adsorbed on Amberllte
IRA-400 strong base resin In the determination of small amounts of uranium in stones and natural waters? 581,582 Uranium Is also adsorbed on Amberllte IRA-400 resin as an as~orbate comple~.m
~orium,
titanium, ~tr~onium,
tung~ten,
and molybdenum are also adsorbed. Uranium complexed with sulfosalluylic acid has been Beparated frOm Zn, CU, with EDTA.
NI,
and Cd.*
The latter m?e complexed
The pH of the solutlon Is kept between 8 and 10.
Separation has been made on Amberllte IRA-401 and Dowt?x-1 reslna. The.uranyl oyanate oomplex formed.by adding potassium cyanate solution to a uranyl salt Is adOorbed by Dowex-1 anion exohange resln.—586
Uranium Is eluted by a dilute hydroahlorlc
acid Oolutlon. Cation -.--.-- exchange. ....-”-..
Although a number of separations of
uranium from various elements have been reported in the literature, the amount Har&
of’ quantitative data reported la rather meager.
has summarized much of the data available on the d3s222
trlbutlon of uranium between cation exchange resins and nLtrlc and hydrochloric acid solutlonO.
Hls curves are reproduced In
Distribution coefflcLent curves
figure 74.
for
other actlnlde
elements: Th, Pa, Np, Pu, are given for comparison~
~evot,
et al.~ 40 have published the distribution curve for uranium between cation exchange resin C.50 and nitric aeld solutlon. Its shape and magnitude are similar to that shown for
225-mo3 system in figure 74.
Ishimorl and Olcun@
the Zeokarbhave fâ&#x20AC;&#x2122;o~nd
that lncre.astng amounts df methanol in nitric acid solutlon (0.18Fl)Inorease the distribution coefficient of uranium for Dowex-50 resin. The elutlon peak positions of a number of ions uranium (IT) and (VI) we
gtven in figure 75 for
chloric acid concentrations. peak positions were caption.
including
various hydro-
The conditions under which the
determined are described in the figure
Ionescu, et al.=
on the distribution of
have studied the effect of acetone
several elemente between cation exchange
resins~ KU-2 and R-21, and dilute hydrochloric acid solutldns. â&#x20AC;&#x153;For fixed hydrochlorfo acid concentrations of lj 2, and ~, maximum uranyl distribution coefficients were found between 60 and 8@
acetone solutlons.
For 4 and 5$ acid eolutlons, D
was found to be considerably lower than for the more dilute acid solutions. Ishimorl and Okun&@
have investigated a number of cation
exchange systems other than those already noted.
Some of their
re~ults, D versus sodium Bulfate, sodium acetate, and oxalic acid concentration, are illustrated tn figure 76.
The adsorp-
tion of uranium by tiwex-50 from solutions of hydroxylamine was found to be pH dependent.
As the pH of the Oolution ~aa
increased, a sharp decrease in D was observed between pH 5 and 6.
Uranyl ion waa not adsorbed by Dowex-50 resin from carbonate
solution. Khopkar
investigated the behavior of
223
I 04
I04
I
,~3
ZEOKARB
I
225
AMBERLITE
u=
I0=
D
#
I I C50
,03
103
D
I
I
FRENCH
IR 120
D
P@
,&
I0=
P# 10
10
,L_l_l-J
M 0246010
0’$
I @
,04
I I I DOwEx 50
I
I 0246BI0
I I I DOWEX 50
D N~
,&
pum
I
PP
10 N> e
Um I
I
,Oa
10
10 -
I04
I03
IOQ
IOe
I 010
M, HN03
1 I I I DOWEX 50
D
D
1
I
1 oz4e
M, HN03
ThW AMBERLITE lR 120
I0=
I
0246BI0
M, HN~
I
10
P&
n
UYI
P#
1
I
0246BI0
0246010
M, HGI
M, HCI
M, HCI
Figure 74. The adsorption of uranium and other actlnlde elements by aatlon exchange reBlns from nltrtc and hydrochlorlo acid solutions. After C. J. Hardy, referenoe 587. The ourves present the data of the following investigators: C. J. Hardy D. Soar 111, J. M. Fletoher, J. Inorg. Nuolear Chem. z, 257 (1956): T’h(~?, Pa(V), U(VI)-HN03. K. F. Sculz, M. J. Herak, CrOat. OhOm. Acta~, 49 (1957): Th(IV)-HCl. R. M. Diamond K. Street, Jr. G. T. Seaborg -J. Am. Chem. Soo. 6 1461 (195!): U(m), NP(~~, (V),(VI), PutIII), (IV),(VI)-HCl. %--’ Ward, G. A. Welch, Unpublished data, U.K.A.ESA., WZnd&cale: N~(V),(VI)-HN03. I. Prevot P. Regnaut Progress In Nuclear Ener&, Series III, ~ 377 (1956): pu(III),lIV)-~03.
224
3.2~ I
I
NP(V)
Pu(vl)
I
1 II
I I I I I
Cm YbSr Y
Cm PuOa LaRa Eu Ba Am
I
U(W)
HCI
I NP(Vl]
6.2~ 1 Y
B I! s! Np(v) u(w) coYb
HCIâ&#x20AC;&#x2122;
1I i ii 1 :; pu(lu) 09b ea Ra Am
93~ 1 I
1
I
1
1
I
HCI
Y Cal PU(M) Eu NP (IV Am U(W)
I
1
I
1 1
!!!
I
erceu
Ac
I
1! I
Pu(lV)Yb
Pu(vl)
I
I
10
1
I
u%) Pu(IW NP(IV)
Pu(vl)
I I N~(:~,cs
I Ac
I
I
I
I 1
1
I
1
I
I II
100
VOLUME
OF
I
I
1000
ELUTRIAPJT
Figure 75. Elution peak positions of various Ions with 3.2,
6.2, 3.3,
and 12.2~ HC1 from Dowex-50 cation exchange resin.
Elutrlent
volume given in drops. After R. M. Diamond, K. Street, Jr., and (1. T. Seaborg, referenoe 591. CondlttonB: Dowex-50 resin, HR form, 250-500 mesh, settling rate approximately 0.5 mn/mlno Column, 10 om long x 1 mm diameter. Flow rate, approximately 0.1 c@nin. Room temperature.
225
100 c 50
m- 50 l-z w
20 10 5
z I
0 SULFATE
I 0.! 0.2 CONGENTRAT!ON, ~
‘c) ACETATE
0.1 0.2 CONCENTRATION,
~
100 90
20 10 ?3
‘0!234!3 H2C2Q4
CQNGENTRATION2
%
Figure 76. The adsorption of uranium by Dowex-pO cation exchange resin from solutions of sodium sulfate~ sodium acetate, and oxallc acid. After T. Ishlmori and H. Okuno, reference 568. Condlttons:
sulfate - 0.5 g resin, NaR form; 5.4 mg U/25 ml; l?a2S04NaN03 mixed solution, [Na] Aoetate - 0.5 g resin, NaR NaNO mixed solution, [Na] Oxal 2 c acid - 0.5 g resin,
226
= 0.30N. term; 5.4 mg U/25 ml; NaOAc= 0.16N. H~for~; 10.8mg u/25 ml.
uranium (VI) on Amberltte IR-120 cation exchange
resin with
hydrochloric, nltria, sulfuric, aoetic, oitrio, and perchloric acids .
Uranium (1.7 mg) adsorbed on a resin bed(l.4
cm) was eluted with 200 ml of various eluants.
x 14.5
Uranium was
quantitatively recovered with 2-4~ HC1, 2-4! HW03, and 1-2M H2S04.
Uranium was Incompletely recovered with ~
H(XL, ~
HN03, 2~ HC104, 2~ aoetfc acid, and 2-5$ citric acid. Sullivan, et al.=
have investigated the distribution of
uranium between Dowex-50 ion exchange resin and perchloric acid media as a function of time and bisulfate ion concentration. Table ~1
lists a number of separations of uranium from
various elements that have been achieved by cation exchange.
4.
Chromatography..
The subject of paper and cellulose chromatography
for the separation of uranium has been reviewed by Rodde~ by Steele and Taverner.—lM
and
Work of Soviet scientists in the
field has been reviewed by Palei~
and by Senyavin.—612 References
to much of the literature may be found in the review article by Kuznetsov, Savvin, and Mikhailov .=
Woks
by Pollart@
and by
Blasius614 — include chromatographic separations of uranium. One of the most successful separations of uranium by filterpaper chromatography makes use of the solvent, 2-methyltetrahydrofuran.~
Of thirty-one metals tested, only ruthenium and rho-
dium, measured as Ru 106- #06
9 and tungsten (W185) were in-
completely separated from uranium (U233).
The results for tin
(Sn113) and antimony (Sb124 ) were inconclusive and the behavior of mercury (Hg203) was similar to that of uranium. An example of the use of cellulose columns in combination with organio solvent for the separation of uranium is that given 616 by Burstall and Wells.—
An ethereal solution containing 5
per cent v/v of nitric aoid is used to extract uranium from a cellulose column.
The nitrates of the alkali metals, alkaline
earths, rare earths, Cu, Ag, Zn, Cd, Al, In, Tl, Ti, Hf, Ge, Sn,Y, 227
Table XXVI.
Separation of Uranium from Various
Elements by Cation Exohange.
Elemental ndxture
Element eluted
u, Th
U-1.7(3~HOl; Th-1.lIj (NH4)2C03
u, Th
U, Th-9@
acetone, %
u, Th
U-~HCl;
Th-~H#04
u, Th
U-=dll.HC1; T&complexlng
u, Th
u.2~HCl;
u, Th
dilute HN03
u, Th
U-().lto 0,4~H+!04;
U, Np(IV)
U-dil. HCl; Np(~)-complexlng
Amberllte IR-120
597
~ Np
adsorb from 1~ HN03; eluted Np ahead Of U with 2g HNoq Sr.O.@HCl; Ce,Y-l~HCl; U-6~HC1; CR-5~ NH4C3
Amberllte IR-120
597
sulfonated phenol formaldehyde type
599
U, F.F’.
admn”b from upanyl nityate mlutfun at pH 1-3; UT=0,2 to O.~! Ii&!04;FoP.-pho~phorie ae.ldand Plm@H3P04 and l~HNo3 ~“ ’03; F.F.-3$ Ns@DTA; U.% NaOAa, 0.25gN~CO3
SOdtUm dlalkyl phosphate
600
u, La
La-O.O@ Na@DTA,
sodium dlalkyl phospha%e
600
u, m
u-oo75~H#04;
U, Ce, Eu, Y
U-ly ~C204; R.E.-Na#DTA
u,
F.P.(cB,sr JY,ce)
u, FOP., Pu
U, R.E.
+
eluti~
agent
HC1, ~0 went
Realn
Referenoe
Amberllte IR-120 (U eluted first) (HSO~)
&5~~C204
592 588
Ku-2 Amberlite ~-120
589
phenol~-dehyde type
593
Wofatit KS Amberlite ~-100
594
algtniq sold Wofatlt KS
595
Thmo05~&#204
pH 4.0; U-x
agent
NaOAa, o.25y N~C03
Eu-6y Hcl Ce, Eu, Y-5~HCl
596
zirconium phosphate 598
Dowex-50
601,602
Amberllte IR-120
603
Amberllte ~C-50
604
U, R.E.
u-2 5y HF
Dowex-50
605
U, Fe, Cut Cd, Nl, Co, ,Mn, R.E.
U, Fe,CU-&5~H2C204; @Nl,Co,Pln-~”3Cl”; R.E.-=~ ammonium altrate
Amberlite IR-120
606
❑
!
U, Ye III), Co(II), CU(II
Fe,Co,Cu-@ N~C03
U,Fe(III)
U,Fe-O.8~HCl (U eluted first) adsorb from O.1~ HN03; Co, Cuj .Ca-O.2MHNO “ U-resin removed from column and washed wlt#
U, Co, Cu, Ca
Na@DTA,
pH 3.0; U-%
NaOAc, o.25~
sodium dlalkyl phosphate
600
Lewatit S1OO
607 600
dlalkylphosphorlc acid
O.25~N~CO3 608 609 61o
Cd-O.5~HCl u,Th,Ac,B1-59jH#204
Dowex-50
U,Th,Ac,Bl,Ra,Pb U, many ions
foreign lonfl-EDTA(Na s.altj~.PH 7J U-H2S04
&uberlite ~C-50
U, many ions
forel ions-EDTA (Na salt}, (a)p.-1.7-1.9 or (bY pH 5.5-7.0 following Fe(CEH)3preotpttatlon;
(a)KU-2or (b) Amberllte DtC-50
611
U, Zr, Ce III),CU, Nl, HE(II f
Zr as ‘&ionic oxalate complex Ce(III), Cu, NI as anionic EDTA” complexes, Hg(II~ aflanlonlo iodide complex tie not adsorbed; U-4~ HC1
Amberllte ~-120
589
U, phosphate
phosphate (N~HP04)
Amberllte ~-120
589
U, Cd
Ku-2
u-~ H.#t)~
F.P. [=] fission products. R.E. [=] rare earth elements. EDTA ~.] ethylsnedlamlnetetraaoetlc acid.
not ,adsorbed; U-4~HCl
Pb, N%, Ta, Cr, W, Te, Mn, Fe, Co, and NI remain stationary or move only sllghtly. column .
Gold reduced with FeS04 Is retained by the
Mercury (II), selenium, arsenic, anthony,
move less rapidly through the column than uranium.
and bismuth Cerlc nitrate
Is extracted as are thorium, zirconium, and scandium nitrates. Cerium in the 111-state Is not extracted. is sensitive to the acid concentration.
Thorium extraction Zirconium extraction iS
Inhibited by phosphate, sulfate, oxalate, and tartrate tons. Scandium extraction is also inhibited by tartrate Ion. precipitated aB meta-stannlc acid.
Large amounts of tin may be
first removed by volatilization as the Iodide. tained If peroxides are absent. dium to an Immobile salt.
Tin is
Vanadium is re-
Ferrous sulfate reduces vana-
Phosphoric acid Ls extracted.
nftrate Inhlblts the extraction of thisacid.
Ferric
The behavior of
molybdenum Is complex. lrldium snd rhodtum are not extracted. Traces of ruthenium emd platinum may be found in the eluent. Palladium Is extracted.
Reduction of platinum and palladtum
with FeS04 results in retention of bulk amounts by the column. Small amounts of sulfate do not Interfere with the extraction of uranium.
Sulfuric acid 2s retained by the column under normal
conditions. e.g.,Au, Sn. column;
HalIdes increase the extraction of other elements, Under normal conditions, HC1 1s retained in the
HEr, HI, bromine and Iodine move slowly down the column.
Molybdenum and arsenic may be adsorbed by the use of activated ~ alumina In conjunction with cellulose. The use of sllioa gel columns combined with organic solvents, dibutyl carbitol and trlbutyl phosphate, and nitric acid have been used for the separation of uranium and plutonlum. QQ2Q A non-ionic phosphorylated resin, dfethyl polyst~enemethylenephosphonate,
may be used to separate uranium (VI) from
Iron (III), lanthanum, zirconium, niobium, thorlum,and retied ftssion products.â&#x20AC;&#x201D;620
Uranium Is adsorbed by the resin from 2
per cent solutlons of dibutyl phosphoric acid. 230
The other elements
are not abBorbed.
Uranium Is eluted with a dlmethyl formamlde-
benzene solutlon. The feaaiblllty of using trlbutyl phoaphate gels for the separation of uranium from Iron (III) and thorium has recently been demonstrated.~
5.
Volatilization.. Uranium may be separated from manY elements by fractional distillation of the volatile compound, uranium hexafluoride.
This method of aeparatlon has been applied to the
recovery of uranium from irradiated fuel elements. Rabinowit&
Katz and
have reviewed many of the early methods for the pre-
paration of’UF6: fluorination of various uranium compounds with elemental fluorine or cobalt trifluorlde, disproportionation UF5 which results in both UF4 and ~6s
of
and the reaOtiOn between
UF4 and dry oxygen which results in U02F2 and ~6.
The latter
two methods axe not very practical from an analytical standpoint. Other fluoridating agents that form ~6
include oeric fluoride,
manganic fluoride, allver difluorides halogen fluorides (e.g., BrF3 and C1F3) and fused metallic fluorides. form fluorides under the conditions that ~6
Moat elements is obtained.
How-
ever, only a small number of these fluorides are volatile.
Hymn,
3 have published a table of some 26 elements having fluorides et al.with boiling or sublimation pointa of 550°C or less.
Included in
this group are the fluorides of boron, silicon, phosphorus, vanadium, sulfurs tungsten, bismuth, plutonium, and the fission products, germanium, araenio, selenium, niobium, molybdenum, ruthenium, antimony, tellurlum, and iodine. of ~G
iS s4.6”C.
The boili~
fiint
Non-volatile fluorides from which uranium 1s
readily separated Include those of the alkali metals, alkaline eartha, rare eartha, Fe, Co, Ni, Ag, Al, ~, 34,622 Hg, Cd, and Zr.
Mn, Tl~ Pb, Zn, Cu,
Uranium doea not form a volatile compound by interaction with anhydrous hydrogen fluoride. 231
Materiala such as I$b,Ta, Aa,
34 Sb, S1, Te, Se, etc. do.â&#x20AC;&#x201D;
The oxides of titanium, tungsten,
and molybdenum reaot slowly with HF.
V205 and VN also reaot
VO, V204 and V203 are not volatilized.~
B1OW1Y.
Warffl
Rodden and
desoribe a procedure that makeB use of both anhydrous
hydrogen fluoride and fluorine in the ~eparatlon of uranium. Possible contaminants of the separated ~6
Include Cr, Ta, W, Mo,
or V. Uranium hexachloride and uranium (IV) borohydride are volatile compeunds for whlah procedures might be developed for the separation of uranium. Uranium may be separated from arsenic, antimony, bismuth, selenium, and tin by volatilization of the latter elements with a mixture of hydrobromlc acid and bromine.
6.
Eleotrochemlcal methods.
~
The electrolysis of dilute sulfurlc acid
solutlons with a mercury cathode results In the qusntltattve deposition of Cr, Fe, Co, Nl, Cu, Zn, Ga, Ge, Mo, Rh, Pd, %, In, Sn, Re, Ir, Pt, Au, Hg, and T1 In the oathode.â&#x20AC;&#x201D; 213
Cd,
Araenlo,
selenium, tellurlum, osmium, and lead are quantitatively separated from the electrolyte, but are not quantitatively i.eposited In the cath~de.~
~ngmese
pletely separated.â&#x20AC;&#x201D;213
, ruthenium, and antimony are inoom-
Uranfum and the remaining actlntde elements,
rare earth elements, the alkali and alkallne earth metals, alumlnum, vanadium, zirconium, nloblum, etc. remain tlon.~
Cast@
and Rodden and Warf~
in solu-
have reviewed the effects
of many variables In the electrolytic separation of the abovenamed elements from uranium. opti~m
According to Rodden and Warf, ~
condttlons for the Purifloatlon of uranium in sulfurlc
acid solutions with a mercury cathode are: electrolyte volume, 50 ml; free sulfuric acid ooncentratlon, l~; current density, as high as practicable with the given acid ooncentratlon
10 amp maximum);
(about
anode, flat platinum spiral or grid just
making contact with the surface of the electrolyte; oathode area,
232
as large aB practicable; sttrring, ❑rface
of the mercury cathode
is stirred rather rapidly; temperature of electrolyte, between 25” and 40”C; mercury for the cathode, pure; anions, chloride, nitrates and phosphate Ions Bhould be absent, or present in only small amounts. Uranium may be deposited electrolytically at the cathode 632 624-631 oxalate,csrbonate,— of a cell from acetate, 640 fluoride,and chlorid~ formate, ~pho~phate,— solutlona.
Many of the uranium electrodepoaltlon proceclurea
have been developed In an effort to prepere thin, uniform fllme for alpha and fission oountlng rather than to separate the elefrom any particular impurity. However, In the work of 624,626 and Cooman~uranlum was separated Smith and co-workers ment
from alkali and alkaline earth metals and zinc. Rodden and WaPf~
Cast-
and
review much of the material pertinent to the
electrodepo61tion of uranium. Electrodlalyals has aohleved a certain amount of importance In the recovery of urantum from leach llquora.
In a review ar-
ticle by Kunln,—643 the followtng cells are presented for conslderation: (-) cathode uo2(~03)2 H2S04
I
anion permeable membrane
anode (+)
(1)
NH4N03
NH4N03
(-) cathode
anion permeable membrane
anode (+)
(2)
Hp~
uo2soq H2S04 H3P04
(-) cathode
anion permeable membrane
U02C12 NaCl H2S04
233
anode (+) NaCl
(3)
(-) cathode
anion membrane
u02c12 NaCl
H
NaCl
cation membrane
anode (+) (4) H#04 ..
H#04
cation permeable membrane
(-) cathode
In
I
mode
(+)
(5)
sold Bysteme (oells 1, 2, 3, and 4), the transport of sulfate,
nttrate, and chloride ions to the anode results in a removal of acid and a subsequent Lnoreafle in PH IIIthe oathode compartment. The uranium, reduaed during electrolyte, U02 or U(HF04)2.
is preolpltated as
In the alkallne system, the transport of so-
dium Ions Is also acoompanled by a rise In PH In the cathode compartment and uranium is again preolpltated as the dioxide or as a mixture of dioxide and sodium polyuranate. The electrodialytlc separation of uranium from meta16 in 644 a complex mixture has been demonstrated by Willard and Flnley.â&#x20AC;&#x201D; An annnonlum blc?arbonate solutfon contalnhg
U, Fe, Ni, Cu, Cr,
Zn, Al, Mo, Mg, and Na Seltsj and traoes of other elements WB electrolyzed in a two-oompartmsnt oell hating a Cation permeable membrane and a mercury cathode.
The solution was first made
the catholyte (electrolyte in the cathode compartment) and elec.trolyzed.
I&on
(8@)p
nlt?kel and copper (95#), tin, and zlno
were removed from solutl.onby deposition.
The bloarbonate solu-
tion was then made the anolyte end eleotmlyzed anode.
at a platlnum
All alumlnum, molybdenum, ammonium, end silioon,and some
sodium and magnesium were separated from the uranium by migration.
Uranium was retained as the carbonate oomplex and was
recovered
as the
oxide by evaporation of the anolyte.
Other features of the eleotrodlalytiabehavior of uranium that may be useful In Its separation end purification ere (1) the retention of uranium during electrodlalysis from a perohlortc
234
catholyte using an anion seleotlve membrane, (2) the dlsSOIUtlQn and separation of Impure UF4, and (3) the feasibility of .electro644 dlalysls In organic aolutlons.—
79 PyrometallurEical processes.
Although pyrometallurglcal
or high
temperature processes have been deBlgned prlmarlly for large scale recovery of fertile material. from Irradiated fuel elements, some of the methods may find application In the radioohemlstry laboratory.
‘&pes of pyrometallurgloal operatlona that have
received considerable attention are(l.) dlstlllatlon, (z.) salt extraction~(~.) molten metal extraction, (q ) oxldatlve slagging, (5 ) electro-ref’ining, and(6 ) decommslticm
Of uranium iodide. 211 These methods have been reviewed by Lawroski.— 1. Plutonium ia concentrated by vacuum distillation from molten uranium At 1500-1800”c. uranium by salts 2. Plutonium is extracted from mlten such as UF or MgCl . Uranium remains in the metellic state. Pl~tonium ig recovered aB a halide salt. 3. Plutonium is extracted by molten metals, such as silver or magnesium, that are immiscible with molten urenium. Fission produots are also extracted. 4. Oxldative slagging involves the preferential formation of the most stable oxides by a molten irradiated fuel element in a limited oxygen environment. These oxides (rare eexths) float to the surface of the molten material and are skimmed off. Other oxides diffuse into the o~cible and through the slag laYer. 5. In eleotro-refining, uranium is dissolved anodioally in a f’used salt bath of alkali or alkaline earth halides that contain a uranium compaund. Noble metals do not dissolve and are deposited as anode sludge. Uranium and chemically similar materials are deposited at the cathode. Alkali, alkaline earth, and rare earth fission products concentrate in the salt bath.. 6. Uranium is recovered as the metal from the thermal decomposition of U14. Zlrconlum and niobium are the principal contaminants. It is not the purpose of this section to describe the
techniques involved in p~ometallurgical
processes.
The interested
reader may consult the many papers presented in ‘Progress in Nuclesr Energy, Series 111, Frocess Chemistry,” volumes 1(1$)56) and 2(1%8),
and In the ‘Proceedings of the International Con235
ference on Peaceful Uses of Atomio Energy, ” volumes 9(1956) and 17(1958). PJ-E Determination of Ureritum The amount of urantum In a sample may be determined by standard methods of analysls: gratimetrlc, volumetric, colort34, 191-195,197,1 98,200,645 metrlc~ spectrophotometrlc9 etc. Because of its natural radioactivity, uranium may also be determined by counttng techniques.
The applicability, In terms of
mass range, of VSXIOUS methods for the determination of uranium IS given In Table XXXVII.~ 1.
Counting teohnlques.
Prinolples of’alpha, beta, and gamma
646 counting are considered In review articles by Steinberg,— 648 and Kof’old-Hansen,—
Hanna,~Deutsoh Jaffey.~
Crouthamel,~
and
All three methods of counting are applloable to
the radiometrlo determination of uranium slnoe both alpha- and beta-emlttlng Isotopes exist (Section III).
Spontaneous fission
half-llves have been determined for ~everal uranium isotopes: $32,
$34,$35,$36,
$38.
These isotopes are too long-lived,
however, to make flsslon counting a praottcal method for their determination. Ionization ohambera are mat of alpha particles. ,pectra of~35and
commonly used for the detection
In figures 77 and 78 are shown the alpha ~33,
respectively.
l%eapectra
were obtained
with a parallel plate, I&lsch .grld ionization chamber using P-10 (90j%argon, 10j%methane) gas. In conjunction
A multl-ohannel analyzer was used
with the Ionization chamber.
samples were prepared by volatilization. the $33
Both U235 and $33
Figure 79 represents
alpha speotrum obtained with a eurface barrier sllloon
solld Btate detector.
Data for this figure was taken from the
same sample as that for figure 78.
It Is readily apparent from
the two figures that the solld state detector gives much better resolution of the alpha groups than does the Ionlzatton chamber.
236
Table ~VII.
Range of Application of VarLoua MethodB for the Determination of Urantum.~
Method
Ran e of application 7micrograms)
Ran e of error T per cent)
Neutron activation
10-4 - 104
*2
Fluoroscope
10-4 - 1
*5 to 50 *1 to
to 5
10
Emlesion spectroscopy
5 x 10-2 - 50
Vlaual chromatography on paper
10-1 - 102
Volumetric (Including mlcrovolumetric) methode
1 - 5 x 105
*0.5 to 5
Autoradiography (a emission) counting of traoke
1 - 10 4
il to
10
10 - 104 50 -5X104
*1 to
3
Calorimetry dibenzoylmethane thiooyanate - HC104 %02 b Alpha counting –
*1 to 3
103 - 105
*1 to 5
50 - 5 x 103
*1 to
Polerography
102 - 104
i2
Potentiometry
2 x 102 - 10 4
Gravlmetric methods
5X104=
10
to 5
*1 to 5 +0.1 to 2
~ Adapted from a table given by A. Simenauer, rei’erence 199. ~50 wg of #38 gives about 20 cpm at 5* geometry. Uranium238 msy be detected in samples having much lower counting rates than this, depending upon the physioal condition of the sample and the presence of extraneous alpha activity. For nd, 1 alpha cpm of uranium a thin Oource with low alpha backg this is the equivalent should be readily detected. ForU$$ of about 2 pg; for other uranium 10otopes, the mass is even less. The data for figure 79, however, was t~en
in 1000 minutes.
The
data for figure 78 was taken in 10 minutes. Alpha particles may be counted also by gaseous, liquld, plastic, and crystalline scintillation detectors.
The resolu-
tion of these detectors i~, in general, leas.than ionization chambers and their application nmre limited. are used to record alpha activity.
Nuclear
emulsions
Such devices as oloud ohambera
are generally not used in the radioohemiatry
laboratory.
Geiger-M&ller counters, proportional counters, and liquld, ,plastic, and crystalline scintillation detectors ere suitable for the counting of ~--emit’ting isotopes, 337,
237
l?3~and~40.
I 0,000
I000
m
100
ENERGY
~
Figure 77. Alpha Bpectrum of a volatilized souroe of &â&#x20AC;&#x2122;35 obtained with a parallel plate, Frlsoh grid lonlzatlon ahamber uBing argon - 1~
9@
methane gee.
D. J. Henderson, Argonne National Laboratory~ Unpublished data.
238
I(3,000
I
I
II I II I III
I
I1 I I
1
I1
I
I I I I I 1 I I I I I I I
000
4
I00
t)
~233
Y
1.62 x 105 yr.
Ionization Chamber Detector I Div. ❑ 20.Okev
l.o
~’’’’’’’’’’’’’’’’’””
o
“’’’B’’’’”
ENERGY
~
Figure 78. Alpha speotrum of a volatilized source of &’33 obtained with a Parallel plate, FrIsch grfd Ionization c~ber argon - l@
methane gas.
using 9@
.
D. J. Henderson, Argonne National Laboratory, UnpubltOhed data.
,
239
I00,000
I
I
I
I
I
I
I
I
1
I
I
I
I
I
I
I
1
I I I I I I I I 1 I I I I I I
>
I 0,000
z F
a U 1-
G. e
2 s
t
8 Q
1000
I
: Q
1’
L(3 In
Cn 12
e“
2 0
Jr I
I 00
1.62 X 105 y~.
U233
Solid
10
1I
I
I
I
I
I
1
I
1
I
1
1
1
Stote Detector I Div.= 7.8 kev
I
1
I
ENERGY
I
1
1
I
1
1
I
1
I
1
1
I
I
I
I
1
~
Figure 79. Alpha spectrum of a volatilized source of $33 a mrfaae
obtained with
barrier silicon detector.
D. W. Engelkemelr, Argonne National Laboratory, Unpublished data.
Sodium iodide-thallium actLvated crystals have gained widespread acceptance aa detectors of gamma radlatlon. ray spectra of $3g~
$37,
$359
$33,
~d
The gamma-
a uranium ore from
the Belgian Congo sre Illustrated In figures 80-84.
The epeotra
were measured by Crouthemel, GatrouBls, and Goslovich~
with a
4-inch diameter x 4-inch thick oylindrioal NaI(Tl) crystal. Not only can the amount of uranium in a sample be determined directly by measuring the disintegration rates of the various isotopes, it oan also be measured indineotly by determining the For such a measurement to be
activity of daughter products.
meaningful, however> the equilibrium condition between the uranium isotope and its daughter must be known. Information on the radioactive decay of the uranium isotopes is given in Section III.
Further information on these isotopes
and their daughter products may be obtained by consulting the ‘Table of Isotopes” compiled by Strommingers Hollsnder, and Seabor#-
andthereferences
given therein.
volumes 8(1956),
3 (1958),and 28 (1958) of the ‘Proceedings of the International Conference on the Peaoeful Uses of Atomic Energym contain a number
of articles on the radiometric determination of uranium.
Referenoe t~ many more artioles is made in the review papers by Meinke.~ 2.
Samp le preparation.
One of’the most important problems to
overcome in the deteotion of alpha p=ticles
and In direct
fission oounting is the preparation of thin foils or sample deposi%B.
This subject has reoeived considerable attention 632,647,650,653,654 and has been reviewed by several authors. Several techniques are available.
The eimplestand
most quanti-
tative is the direct evaporation of an aliquot of a sample.
The
distribution of such deposits are generally not very uniform. This
may
be improved upon by the addition of a ~preading agent
such as tetraethyleneglycol, ‘PEG. Painting techniques may be used to build up fairly uniform deposits of several milligrams 241
per 8quare oentlmeter.w
Uranyl nitrate lf3d10801ved In
alcohol and added to a dilute Solution of Zapon In Zapon thinner or
This solution 16 painted over a
aelluloae In SIW1 acetate.
metal backing, allowed to dry, and then baked or ignited at a mltable
temperature.
For aluminum backing, temperature
550e to 600”c are satisfactory.
of
For platinum”, higher tempera-
The thickness of the uranium
tures (800”c) are preferred.
depoalt iB lnareased by repeatedly painting and baking the foil. I00
I I II I I I No enternol obaorbm
90
80 70 1~ ~
60 50
2 b A x
40
E : c a & z
30
a : ; i 5 ~ Q *
~
~
20
?
/ r
\
A
10 0
I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I 1 I I 1ENERGY ~ Ftgure 80.
Gamma-ray speotwm
of $39
obtained with a 4-lnah diameter x
4-inoh thlak ayllndrloal NaI(Tl) crystal. After C. E. Crouthamel, C. Ga&rousis, S. J. (loslovich, reference 649. 242
90 80 70 60 50 40 30 20 10 0
Figure 81. Gamma-ray spectrum of U237 obtained with a 4-inch diameter x 4-inch thiok cylindrlcalNaI(Tl) crystal. After C. E. Crouthamel, C. GatrouBfs, S. J, GOslOViCh, reference 649.
I00
1111
I Ill I I I I I I I I I I I I I I 1 [ I I I I I I I I I I I I I I I I I I I I I I I I I I I I ?u~~s 7.1 x Iosyr. NO ●rnternal ab60rber
90
660matry
80
counted
70 . ;
60
A x s
J
50 40 30
20 10 0
10%
I Div. = 6.6 kOV
—
a 0 ? n J
30 min. oftar
66porotlon
from
dauffht0r6,
10 mgs. U
● m u 3
* 2 m m e 3
E > : m
m w
I
ENERGY ~ Figure 82. Gamma-ray spectrum of U235 obtained with a 4-inch diameter x b-inch thick cylindrical NaI(Tl) crystal. After C. E. Crouthamel, C. Gatrou8iB, S. J. Goslovlch, reference 649.
[00
m-i-i-TT-nT-1”1
I“’’’I’’’’’’’’’” T
90
T r-1-irn-l--~
q
U233
80
o m a m
25mg/cma Sr(N03)2 Geometry 10% I Div. = 6.4 kev
70
~ m u c o E
Mose Anolysis 7.4 ppm 238 < I ppm 236
!
L
60
s z= s =_ @)wg em”
a o ? * -1
40 30
E > ~ m
20 10 0
< I ppm Z35 c 2 ppm 234
z
50
G I ppm 232 : \
[
Ma 1 J-III
1.62 x @yL
a m a
I I I I I I I I l,, 1. I I I I “1 I I I I I I I I I I I I 1 I 1 I I I I I I I I I I I I I I II
I I I I
ENERGY ~ Figure 83. Gamma-ray spectrum of u233 obtained with a 4-inch diameter x 4-inch thick cylindrical NaI(Tl) crystal. After C. E. Crouthamel, C. Gatrou~ls, S. J. Gaalovich, re~erence 649.
100
I I I I I I VI I I I I I I I I I I I 1 1 1 1 z_ z m
z
90
I
<Belgium Coneo-handpicho
80 70 60 50 40
30 II — 1 II
20
y
f
I
o—:—
10
o~
I I I I
Ill
I I h 1 I 1 I I I I I I I I I 1 I I I I 1 I Ii+r%u ENERGY’ Figure 84.
Ganma-ray spectrum of uranium ore from the Belglan Congo obtained with a 4-inah dtameter x ~lnoh
thick cylindrical NaI(Tl) crystal.
After C. E. Crouthamel, C. Gatrousls, S. J. (30slovicth,referenoe 649.
Sample8 of the metastable $35 by electrostatically air.-
isomer have been prepared
colleatlng the recoil atoms of Pu239 In
A negative potential of 6eve~al hundred volts wae
applied to the metalllo colleotlon plate. Carswell and Mllste&
have suooeeded In preparing thin
souraes by a spraying technique.
The material to be deposited
la dlaeolved atethe nitrate In an organic acetone).
solvent (alcohol or
l%e solution Is drawn Into a fine glass oaplllary
246
tube and Oprayed onto the baokhg
material by applylng an
electrlc field. Electrodeposltion
Is a generally E4atlsfactory method for
preparing uniform samples with quantitative or nearly quantitative yields.
Uranium has been plated from a variety of solu-
tions: acetate, ~~bonate,=
34, 623,628-631 ~omte fluo~lde,623#632#641
639 Omlate #â&#x20AC;&#x201D;
623,633.638
and ~hlor~de~~
A satis-
factory electrolyte for the depoOttlon of uranium Is 0.4~ ammonium oxalate.â&#x20AC;&#x201D;654
A rotating platinum anode Is used to stir
the solutlon placed In a vertical cylindrical cell.
The cell
is made of glass, lucite, or some other chemically Inert material. The cathode on which the uranium Is to be depaslted la tlioroughly cleansed and made the bottom of the cell.
The assembled cell
is placed In a hot water bath and the temperature kept at about 80â&#x20AC;?c .
A current density of approximately 0.1 amp/cm2 Is u~ed.
The deposition Is influenced strongly by the rate of stlrrlng, ~ current density, and presence of foretgn Ions. Vacuum sublhation
provides an excellent meens for the
preparation of thin deposits of uranium. uranium acetylacetonate, U(C5~02)4J
The sublimation of
has been uEed.
A more
convenient method Is the sublimation of uranium oxides.
A
uranium salt solutlon 1s placed on a tungsten or tantalum ribbon supported between two electrodes.
The solution Ie dried by a
heat lamp or by pasalng a low current through the metal ribbon. The sample backing material Is suspended at a suitable height above the metal ribbon. unit and evacuated.
A bell jar is placed over the astiembled
The uranium is volatilized by Increasing
the current through the metal ribbon.
The uniformity Of the
deposit depends upon the distance between the ribbon and the backing plate.
The collection efficiency also depends upon
this distance but in an Inverse manner to that of deposit unlformity.
Usually a compromise i~ made between collectlon
efficiency an; sample uniformity.
247
Much of the uranium that is
not collected on the sample plate can be recovered from maaklng plates and glaee chimneys plaoed between the filament and baclflng material.
The collection efflolency
may also be improved by
subliming from furnacea so that the beam of uranium molecules is directed toward the backing plate.
The furnace iE heated
by electron bombardment or InductIon heating. 3.
Activation Analy61s.
In activation analysis, a nucllde
Irradiated by neu~rons, gamma rays, or transfofid
charged particles Is
Into a radloacttve nucllde more easily detected than
the original one.
The amount
of
original
material
mined either absolutely or comparatively.
may
be
deter-
For an absolute deter-
mlnation,the cross section of the reaotlon~ the Irradiation fluxl and the disintegration rate of the reaction product must be known or determined.
For comparative analy~is, a substance of unknown
mass is Irradiated simultaneously wltha known maes.
similar substance of
The positions of these two substances are either
side by side or, if separated~ in positions of like flux.
The
reaction produot aotlvltles of the two samples are compared to give the relative masses of the starting materials.
The com-
parative technique 1s, In general, muoh easier to apply.
The
uncertainties of many variables are eliminated by relative measurements.
Aotlvatlon with thermal neutrons may be successfully employed as a method of analysis fo~.natural uranium, uranium-
236, and the fissionable Isotopes of uranium. oonsists of U’38(~.~),
U’35(0.7~),
Natural uranium
and @34(0.0057~).~
The
prinolpal reactlormof these nuolides with thermal neutrons are:
* Half-lives given below the arrow are taken from the “Table of Isotopes,n reference 651. The value of ~ for the flsslon of $35 IS t&en from ‘Neutron Cross SectIons,n reference 660.
248
*
#35
+ nl+Fisaion
$34
+ .1+
moducts
+ 2.47 neutrons,
$35. uranium pre6ent in a ample
The amount of natural
determined from the amount of $39, formed after Irradiation.
Np23~ or m239
may then be aatlvtty
Measurement of the PU239 activity,
however, requlreB either a fairly large amount of $38, irradiation period, or a combination of the two.
a long
The amcunt of
natural uranium may also be determined from the fission of uranium-235 either by (1) fission counting the sample, (2) iso140 lating and counting a fission product suah as Ba or Te132*, or
(3) measuring the total gannna activity induced in the s~ple
by a short neutron irradiation.= of $34
results in $35
Thermal neutron irradiation
and is of little value in the determina-
tion of natural uranium. Neutron irradiation of $36
gives $37,
having a half-life of 6.75 days.â&#x20AC;&#x201D;651
a beta-emmiter
It 16 readily identified
through its beta decay, associated gannnarays, and half-life. Uranium-238 irradiated with fast neutrons also producee $37, U238(n,2n) $37.
Tâ&#x20AC;&#x2122;hecross section forthis
reaction has been
determined with incident neutron energies from 6 to 10 Mev andat16Mev.~ Activation analysis by fission counting is of value only if one fissioning nuclide is present or if the amounts of other fissioning nuclides present are known and corrections can be made for them.
The same is true for the isolation and deter-,
mination of fission products.
Uranium isotopes that are
fissionable with thermel neutrons together with their thermal 660 neutron fission cross sections exe:â&#x20AC;&#x201D; &30
25 ~ 10 b~ns
$31
400 t 300 barns
*The fission product nuclides Ba
140
and Te132 are chosen since
they sre free from Interfering reactions and ere produced in good yields.
249
Other than $35,
$33
+32
80 + 20 barns
$33 $35
527 t 4 barns 582 * 6 barns
$39
14 k 3 b~s*
is the best uranium Imtope
by fission oountlng or fission produot analysis. may possibly be determined in thi.B manne~.
to determine Uranium-232
The other isotopes
are of such short half-life that analysis of their own radiations Is a much better means for their Identlflcatlon. Excitation functions have been determined for a number of reactions with charged particles or gamma ray8 Incident on uranium isotopes. analysis. (1)
TheBe reactlona may be used for activation
For abeolute analyalsp It Bhould be pointed out that
the CrOBB
Sections reported are sometimes aub~ect to con-
elderable error; (2) energy
determinations of the tncomlng
particle or ray are also subject to error; and (3) the reaotion produot can often be produced by a number of reaotions.
Com-
parative analys16 appears to be a much better method for the determination of uranium.
For gaunna=ay (bremsstmahlung) activation,
simultaneous Irradiations in a like flux are fairly easy to accomplish.
The two samples~ unknowâ&#x20AC;?n and standard, are mechani-
cally rotated In the gamma-ray beam.
For charged particle
actlvatlon, the simultaneous Irradlatlon of twb sanples In a llke flux may require some Ingenuity on the part of the exW perimeter. A partial list of reactions between uranium isotopes and charged particles or gamma rays for which exoitatlon functione
*
Pile neutrons.
â&#x20AC;&#x2DC;Because of the short range of charged particles, Irradlatlons are generally made with targets attaohed to or within the vacuum system of the accelerator. To maihtaln the systemts vacuum requirements, to 00Q1 the eamples properly, and to Irradiate the samples simultaneously In a like flux may present some d~ty In equipment design. 250
or Individual croBO sections have been determined Is given below:
Protons U@(p,t)u236
=
Deuterons &3(d~2n)Np236238 663,664 663664 @38(d~4n)N~9
664,665
&38(d,p)&
$34( d,n)Np2:~4~6 ~34(d, 2n)Np233 ~ &34(d,3n)Np
&38(d,t;d,p2n)&37 &38(d, t)&37 ~
@33(d,n)Np234 ~33(d,Z%)Np2~
236 664,666 &’35(d, n)Np ~35(d,2n)NP~~ ~~’~~ &35(d,3n)Np233 666 s &35(d,4n)Np
—
~ W m
&33(d,3n)Ifp232 = U233(d,an)Pa 230 ~ &33(cc,F)ZA=
—
Alpha
F34(a,4n)Pu
2+
lF33(a,n)Pu236 LF’33(a,2n)Pu235
668,67o
9 552
T333(a,3n)Pu234 =
LF36(a,4n)Pu
236
F33(a,4n)Pu233 = &33(a;5n) ~~~3~% ~233(a,p)Np 235 ~
668 —
@33(a,Pn)Np 234669 &33(a,P2n)Np233 ~
C?35(a,n)PU238 W&? &35(a,2n)W~~ %,669
$33(a,p3n& &33(a,F) —
TF’35(a,3n)Pu t+’35(a,4n)Pu235
552
Carbon Ions &38( fJ12,4n)cf246 EE #38(c12,6n)cf
-
244 242 ~ ~
~38(C12,a4n)Cm
L?33(y,N) ~
251
—
The analysis of uranium by activation methods ia reviewed by Kooh,~who
glvea references to much of the literature.
dSO
Dissolution of Uranium Samples
IV-F . 1. Metalllc uranium.
Uranium metal diseolvea In nitric acid to form uranyl 3“ nitrate. With massive amounts of uranium the rate of’dLssolutlon Is moderately raptd.~ turnings, powder, m
The reaction between uranium
sintered metal
and nitric acid vapors or
nitrogen dioxide may occur with exploslve violence.
~
Oxides
of nitrogen are the principal gaseous products in the dissolution of the metal by HNO~.
The presence of oswgen in the dissolver
system tends to reduce the emisston of these oxides. ~
me
rate of “dissolution of large amounts of metallic uranium may be increased by the addition of small amounts of sulfuric,% phosphorlc,mor H2S04.
perchlorl=acld
to the nitric acid.
Hot concentrated sulfuric acid attaoks uranium metal
slowly forming uranium (IV) sulfate.~
Sulfurlc acid-hydrogen
peroxide mtitures react slowly with the metal. at 75°C forming 682 The addition of small amounts of chloride uranyl sulfate.— or fluoride to ~S04
- H202 ~xtures
increases the dissolution
rate.= ~ H3P04 . Cold 85$ phosphoric acid attackg uranium metal slowly. —— Concentration of the acid by heating produoes a fairly rapid reaction In whioh uranium (IV) phosphate is formed.
If heated
too long, a chemically inert, glassy substance is formed. HC104. Uranium mtal
is inert toward cold, dilute perchlori.c acid.
As the concentration is inareased by heating a point is reached at
which the reaction
Oxidizing
proceeds with violence._
agents added to dilute perchloric acid dissolve the metal. ~ HC1. metal.
Concentrated hydrochloric acid vigorously attacks uranium Dilution of the acid diminishes the attack.
But even
with 43 HC1 there Is a rapid evolution of hydrogen.—682
252
*
finely divided, black precipitate soon forms titer dissolution begins.
This precipitate Is not dissolved by heating.
Only by
the addltlon of oxidizing agenta (hydrogen peroxide, bromine, chlorate, nltratc, persulfate, dlchromate, or ferric ions) does the precipitate dissolve.
Gaseou6 chlorine, a~dtidby small
amounts of iror or Iodine, also oxidizes and solubillzes the The addition of small amounts of fluoslllcla
uranium precipitate. aclz
or large amounts of phosphoric aci=
to the hydro-
chloric acid prevents formation of the blaok preclpltiate during the dissolution of uranium metal. HF. —
The reaction of hydrofluoric sold with uranium metal is slow
even at temperatures of 800-900C.~
The reaction IS lnhlblted
by the fornwtion of insoluble UF4 on the surface of the metal. HBr.
Hydrobromic acid attacks metallic uranium in manner
similar to, but slower than, hydrochloric acid.~
The black
precipitate is formed. HI.
The reaotion between uranium metal and hydridlc acid is
Zw.= Organic acids.
Acetic, formic, proptonlo, and butyrlc acids
react rapidly with uranium In the presence of hydrogen chloride.
~
Benzoic acid in ether reacts with the metal, forming the benzoatc.677
Acetyl ahlorlde and acetic anhydride react to form
uranous acetate.= Miscellaneous
solvents.
Uranium Is dissolved in a number of
682 media other than acids: 34,677, solutions of heavy metal salts (silver perchlorate,~ tats),
alkaune
cupric anmmnlum chlorid~
peroxide solutions (NaOH-~02
685
or ace- 7
or Na202-H20
solutions),
solutions of bromine and ethyl acetate,682*688 682 hydrogen chlorlde and hydrogen chloride and ethyl aoetate,— 682 * acetone,— and nttrogen dloxtde ‘and hydroger fluoride. Table XXXVIII denotes qualitatively some solutlons that 682 satisfactorily dissolve uranLum.— Anodic dissolution.
Metallic uranium may be dissolved elec-
253
trolytlcally by anode oxidation. have been
~eed.-
A variety of electrolyte di~~~l~t~o~fl have been
s~t~~f’a~~py
made with aulfuria acid,—682 nitric acid,= phosphoric acid aontainlng nitrate,—6%
tartarlc acid,=
and sodium bicarbonate.
~
The eaBe with which uranium alloys are
2. AlloyEI of uranium.
dlaaolved depends largely upon the chemioal behavior of the alloying metal.
LarBe=
has reviewed the diaBolutlon of
some of the more common uranium alloys.
Table ~11
aummarizea
the effeot of various reagents on these alloys. 3. Compounds of uranium. of uranium compounds.
Table II liBts solvents for a number
General Review references 2, 4~ 5, and
7 (Section I) aover the chemical properties of these and other compounds more fully. Table XX17iTII. ReagentO for the Dlsaolutlon of Uranium and Its Alloys.~ S = Satisfactory Description
HNO 3
%&a
N = unsatisfactory Nitric - HC1 + HF Ox
HC1-
Br2-
NaOH-
‘tOAo
EtOAc
H202
u
s
s
s
s
s
s
s
U-Zr
N
N
s
N
N
s
N
N
N
s
N
N
s
s
U-Fe
s
s
s
s
s
s
N
U-Cr
N
N
N
s
s
s
U-RU
N
s
N
N
N
N
N N
U-MO
N
s
N
s
N
s
U-FiSBiU~
N
s
N
N
N
N
s N
U-SIG
s
U-PU
s
s
s N
s
s
s
N
u-m
“
—a R. P. Larsen, referenoe 682. ~ Alloys containing from 1 to $
Zr, Mo, Ru, Rh, Pd, and Ce.
~ Fluoride must be added to dissolve Zr. ~ Nitric
acid dlBaoluttons leave S1 residue, but nitrLa-hydro-
fluoric aoid dissolutions can easily lead to volatilization of fluosilicic aoid. ~ W“itself
iB not readily dissolved in nitrio acid, hydrochloric
acid being preferable. 254
The dissolution of uranium oxides is of considerable Interest since uranium samples prepared as accelerator targets, for neutron irradiations, or samples found In the natural state are frequently In the form of oxides.
Also, many compounds of
uranium may be transformed to the ‘oxide by heating, hydrolyses, or fusion.
All of the oxides, UO ~, ‘3°8, and U02, are soluble
in nltrlc acid, forming uranyl nitrate. mineral acids.
u 08 and U02 are dissolved by fuming with
perchlorla acid~~
$
sulfuric acid.—34 dissolution.~
U03 is soluble In other
They are slowly dissolvyd in hot concentrated
The presence of fluoride accelerates this Alkaline peroxldeB react with Uranium oxides
to form soluble peruranate~.= 4. Meteorites, minerals, and.ores.
The extraction of uranium
from natural deposits may be accomplished by decomposition and dissolution of the entire sample Includlng uranium or by leachfng the uranium from the stiple. tate
the recovery.
C&indtng and roasting facili-
Roastfng removes organic material.
It also
helps form soluble uranium compounds. Decomposition of the sample may be accomplished by acid attack, by fusion,or by a combination of the two. Indlvldually or In combination, may be uEed. hydrofluorlc
MLneral acids,
The presence of
acid generally aids In dissolution.
Ores, sand,
etc. may be fused with sodium carbonate, sodium hydroxide, sodtum peroxide, sodium bisulfate, sodium chlorlde and sodium hydroxide, ammonium sulfate, potasalum btfluorlde, and magThe melt is solublllzed In water or acid
nesium oxide.-
and the separation of uranium made by procedures outllned In Section IV-D.
Rodden and Warffl have described a number of
procedures In which uranium was made soluble by actd attack or by fusion methods.
The recovery of uranium from monazlte sands * ha~ been reported by Calklns, et al. Acid and alkaline leaching~e for the recoven
used on an Industrial scale
of uranium from its ores.
255
In acid leachlng,
nlt~lc,
hydrmhlorlo,
or sulfuric
sold
may be ymed.~
Indun-
trleilly, sulfurlo sold ID used beoauee of ito eoonomy. agents (Fe(III),.Mn02, eta.) are uned b A se~ation”of
uranium (VI).
Omldizln$
oonvert uranium (IV) to
uranium and thorium with an omallo
reported.B“
sold-nitrlo sold leaoh oolutlon hae been
In alkaline leaehing, various oombltitlons of alkellne carbonates, hydroxides, and peroxideahave been uoed.~
Indus-
trially,. uranlum”is dissolved by alkellne carbonates ae the
uo2(co3).:-
oomplex.
oxygen or othm
suitable oxidants are used
to oonvert uranium (IV) to uranium (VI). fo~d
w-l
ions ere
by the dlsoolution of urantum in carbchate solutlone. The
presenoe of blmrbonate
ion In the dlsaolvlng ”solution prevents
the preolpitation of uranium. end alk@ine
The recovery of.uranhnnby
acid
leaohing 18 reviewed In General Review re~erenoe
13 (Sectton I). 5. BIo1oR1cM
s-
len.
The detemnlnatlon of uranium In bi,olo-
glcal samples Is reviewed by 9teadman.
m
Uranium maybe
traoted and determined direatly from llquld BempleB. may also be ached, ae me traction.
ealld mmplea,
A8hlng may be cerrted at
ex-
The eample
prtor to uranium ex-
ae a“wet otidry procetm.
Wet-aehlng Is comnmnly done with a nltrlc aotd t301utlon. Aching may be completed with perohlorlc acid. mst acid.
However, extrems oautlon
be exerclaed when heating organlo matertaM
with perohlorto
The aihed reBldue 10 dlaBolved In aoid and the uranium
determination continued from there. “carrted to completion.
Iiet-ashlng need not be
AnalyslB may be made upon the saqple
after It has been thoroughly digested in sold. 6. Alr dunt Bemplea. on filter papers.
Samples of air dust are oonmmly
oolleoted
The urenlum may be dio~olved by digesting
the muuple,ln nltrlo acid aolutton or the sample may be aBhed and the re~idue dlBBolved in sold.
7.56
v. Collection of Detailed Procedures A procedure for the determination of uranium may entail one or more purification steps aa outlined in the preceding eectione.
For example, uranium may be Beparated from impurities
by a flerieaof solvent solvents.
extraction
with one or more difi’erent
These may be interspersed with precipitation and/or
ion exchange methods.
The procedures deBcribed herein have
been gathered from,project reports, the open literature, and by private conmmnlcation.
Only a limited number are presented.
They have been selected because they repre~ent many of the reparation methodO already det3cribed or because they represent different problems in hemdling samples: problems of dissolution, extraction in the presence of high beta-gamma activity, etc. A number of the procedures described do not make use of the raThe method of separation
diometric determination of uranium.
in these procedures, however, is applicable to radiochemical analysls and is, therefore~ inaluded.
A number of papers and
reports describeg In detailp procedures for the determination of uranium. Thetie should be noted.
The work of Rodden and
liarf’~ has frequently been mentioned in this paper.
In addi-
tion to procedure! for the precipitation, solvent extraction, volatilization, and electrodeposition of uranium, these authors ~ve
presented a number of selected procedures for the solution
of ores and minerals and the Oeparation and determination of uranium.
Procedures for the analtiical, determination in naturally
occurring materials have also been deOcribed by Rodden and ~Sohoeller Tregonning,—366 Griuualdi, May, Fletoher, and ‘Titcomb, and ’Powell,~
and in the ‘Handbook of Chemical Determination
H698 of Uranium in Minerals and OreB. — Moor&on
me
recent ~blication
by
extraction with amines contains a collection of pro-
cedures, many of which have to do with the separation af uranium. 257
HIOOEDURE 1: Uranium-237. Source: B. Warren, LA-1567 (1953) p. 18. Editor’s note: Uranium-237 may be separated from fission product$, neptunium,and plutonium more easily by ion exchange and/or solvent extraction techniques (See, for example, Procedure 7). The following procedure 1s, however, an excellent example of uranium purification by precipitation methods.
1. Introduotlon The significant steps in the determination of $37
in ma-
terials containing fission products, neptunium and plutonium are the following.
Rare-earth, neptunium, and plutonium activities
are removed by appropriate lanthanum fluoride scavenging flteps in the preeence of hydroxylamine hydrochloride.
The latter
reagent serves to reduce both neptunium and plutonium so that they may be carried down, and also to oomplex uranium and prevent Its later removal in Iron scavenging steps.
Barium and
zirconium are precipitated by barium fluozirconate scavenging. following a oycle of ferrio hydroxide scavenging and ammonium dluranate preolpitation steps, uranium is reduced by zinc metal in hydrochloric acid medium and preaipltated, presumably as U(OH)4, with ammonium hydroxide.
The uranium is Further purified
by alternate conversions to tetrafluoride and hydroxide. Th234(UXl)
which has grown in from $38
24.ld
i, removed by a zirconium
Iodate soavenge and the uranium is converted to ammonium diuranate. Uranium is finally plated from nitric acid medium onto a platinum foil.
‘After flaming of the foil and weighing, uranium is beta-
counted as U308.
Chemical yields average 50 to 65$.
Quadrupli-
cate determinations require approximately 8 hours. 2. F38
carrier: lml
Reagents
containing 10mg
of (5000/1) uranium.
Pre-
paration: Weigh out 1 gm of U metal, dissolve in transfer to a 100-ml volumetric flask. Cone” ’03’ Make up to volume, adjusting the final solution
258
PROCEDURE 1 (Continued) to ~
in HNO~.
The carrier is atandardlzed by
pipetlng 1 ml allquots Into a 000-Coors procelaln crualble, evaporating to dryness, ignltlng at 800*, for 45 mln, and wetghtng as ~308. La cerrler:
10 mg La/ml (added aB La(N03)3 . 6H20 in H20)
Ba carrier;
10 mg Ba/ml (added as Ba(N03)2 In ~0)
Zr mrrier:
10 mg Zr/ml (added as ZrO(N03)2
Fe carrier:
10 mg Fe/ml (added as Fe(N03)3 “ 9~0
●
2~0
in l~HN03) in very dilute
HN03) HC1 :
cone.
H-No : 3 HNO : 3 HN03 : HF:
ly 8! cone.
cone.
~SO~:
oona. 0.35y
H103 :
NH40H: Cone. N%oH
“ ‘C1:
5M
(NH4)2C204
~aqueoue Br2: llqu%d Zn metal:
20 mesh, granular
MethanOl: anhydrouB Methyl red Indloator solutlon: 3.
O.1* In 905 ethanol.
Equ@nent
Fisher burner Centrifuge Block fOr holdlng centrifuge tube6 40-Inl
centrifuge tubes:
Pyrex 8140 (10 per sample)
000-Coors porcelain crucibles (one per standardization) Pt-tipped tweezers Pipets:
assorted sizes
259
PROCEDURE 1 (Continued) Stlrrlng rods Plattig assembly:
1 cell per allquot of’ sample source of current - Fisher Powerhouse (D.C.)
with variable resistance In series with oells. Cell - Brass base (3” x 3n) for holding pt cathode; 5-roil pt circular 2 n diameter disk (cathode); gasket (Koroseal-Upholstery 36681) to seal oathode and ohlmney; glass chimney, 2“ diameter, Q“ high, with b ears at height of 3“; 1 1/4” steel springs for holding chimney to base; rotating pt anode.
The cell Is heated for 1 3/Q hours at 105° after
assembly to insure formation of seal between glass and Pt. Water bath for cell - Autemp heater; 6“ crystallizing dish (for water bath); rubber pad for holding cell.
4. Step 1.
Procedure
Add 1 ml of standard U oarrler to an allquot of
sample In a 40-ml long taper aentrlfuge tube. 10 ml, heat to bolllng, and precipitate
Dilute to about
(NH4)2U207 by the drop-
wlse addltlon of cone. NH40H . Step 2.
Centrifuge and discard the supernate.
Step 3.
Mssolve
add 5.4 ml of ~0, ~OH
●
HC1.
Step 4. mln.
the precipitate in 1 to 2 ml of 1~ HN03, 3 drops of La carrier, and 10 drops of 5~
Allow to stand for 5 min. Add 3 drops of conc. HF and allow to stand for 5
Centrifuge for 5 rein, transfer supernate to a 40-ml
centrifuge tube, and discard the precipitate.
Step 5.
Add 3 drops of w
carrier and let stand for 5 min.
Centrifuge for 5 rein, transfer supernate to a 40-ml centrifuge tube, and discard the precipitate. Step 6.
Add 3 drops of Zr oarrler and 15 drops of Ba
260
PROCEDURE 1 (Continued) Centrifuge for 5 min and transfer the supernate to a
carrier.
!O-ml centrifuge tube, discarding the precipitate. St@p 7.
Add hdrop6
of aono. H@04
TranOfer the supernate to a ~-ml
and centrifuge for5
min.
Centrlruge tube and discati
the precipitate. Step 8. Add 2 drops of Fe carrter, heat the Bolution to boiling, and prectpltate Fe(OH)
by the addition of cone. NH40H . 3 Cool the tube under cold H20, centrifuge for 2-1/2 mln, and transfer the supernate to a 40-ml centrifuge tube, discarding the precipitate. Add 0.4 to 0.5 ml of liquid Br2 (Note 1) slowly to
m“
slight exces8 and boll the solutlon to a light yellow color. Add cone. NH40H until (NH4)2U20T precipitate forms.
Cool un-
der cold water, centrifuge, and Oave the precipitate. Add 1 to 2 ml of ~
Step 10.
HN03 and 10 ml of H20, heat
the solution to boiling, and add cone. NH40H to reprecipitate (~4)2U2°7a
Centrifuge and save the precipitate. Add 1 to 2 ml of 1~ HN03, 10 ml of H20, 10 drops
Step 11.
Of 5M — NH20H “ HC1, and 2 drops of Fe carrier. 5 min.
Let stand for
Heat the solution to boiling and precipitate Fe(OH)3
by addition of cone. NH40H.
Cool the tube under cold H20,
centrifuge for 2-1/2 rein, and tranefer the supernate to a 401111centrifuge tube, discarding the precipitate. Step 12.
Repeat Step 9.
Step 13.
Add 1 ml of cone. HC1, 10 ml of H20, heat the
solution to boiling and precipitate (NH4)2U207 with cone. NH40H. Cool the tube, centrifuge, and save the precipitate. Step 14.
Dissolve the precipitate in 1 ml of cone. HC1 and
10 ml of H20.
Add 2 gm of Zn metal (20 mesh, granular), and
heat the mixture until the solution turns brown. tional minute.
261
Heat 1 addi-
PROCEDURE 1 (Continued)
EkEL22”
Let Otand until the vlgoroua gas evolution aubsldes
and decant Into .a 40-ml oentrlfuge tube.
Dlsoard the Zn.
Step 1.6. Heat the solution to boiling and precipitate U(OH)4 (?) with cone. NH40H. black. )
(The precipitate will be greeni~h-
Centrifuge and save the preclpttate.
Step 17.
Dissolve the precipitate In 10 drops of cono. HC1.
Add 5 ml of F$O and 4 drops of cone. HF.
Stir vigorously
UF4 precipitates , add 7 drops of cone.
NH OH and stir. 4 trifuge 5 mln and save the “precipitate. Step 18.
until Cen-
Add 1 ml of cone. “HC1,heat slightly, add 10 ml of
H20, and heat the solutlon to boiling (the precipitate should Add cono.
dissolve).
NH40H and precipitate U(OH)K (?) (greenlsh-
black preclpltate). Step 1!3. Repeat Step 17, except that 4ml
ofI$O
are added
instead of 5. Step 20.
Add 1 ml of cone. HN03 and heat until N02 ceases
to be evolved.
Add 10 ml of ~0
with cone. NH40H.
and precipitate (NH4)2U207
Centrifuge, discard the supernate, and
dissolve the precipitate in 1 ml of cono. HN03. Add 10 ml Of 1-$0, 4 drops of Zr carrier, and 1 ml
Step 21.
of 0.35~ H103.
Centrifuge, transfer the supernate to a 40-ml
centrlfige tube, and dlsoard the precipitate. Heat the solution to boiling and prectpltate
Step 22. (~4)2U207
with cone. NH40H.
~
Centrifuge and discard the supernate.
Dissolve the pre~lp~tate In 1 to 2 ~
dilute with 10 ml of ~0,
and centrifuge.
of’ %~03D
Transfer the super=-
nate to a 40-ml centrifuge tube and discard the precipitate. Step 24.
Repreclpltate
and adding cone. NH40H. Step 25.
(NH4)2U207 by boiling the so~utlon
Centrifuge and save the precipitate.
Add 5 drops of 8~HN03
cell which oontains 10 ml of SO
and transfer to the plating
and 3 drops of 8~ ~03.
Rinse
the centrifuge tube with three washes eaoh consisting of 5 262
PROCEDURE 1 (Continued) drops of 8M HN03 and 0.5 ml of H20, transferring the washings to the plattng cell. Step 26.
Add 10 ml Of 4% (~4)2C204
and wash
the oell walls
down with approximately 5 ml of I-$0. The total volume In the cell should be about 40 ml. Add 5 drops of methyl red solution, and eonc.
~“
NH40H drop-wise until the solution turns yellow.
Add 8~HNo
3
until the solution turns red or orange (one drop la usually required); then add 3 drop~ of HN03 in excess. Step 28. 80 to 90°.
Plate for 1-1/2 hours at 1.5 amp and 8 volts at For the first 30 rein, at 10-min intervals add
sufficient 8N HN03 to make the solution red to methyl red.
40 rein, add 3 drops of cone. NH40H, or enough to tie
At
the SOIU-
tion yellow to the indicator. ~
‘ash don
me
cell ‘alla w~thqo
to replenlsh that
lost by evaporation, and continue electrolysis for an additional 50 min. Remove plate, wash with H20 and methanol.
~“
plate for 1 min.
Cool, weigh as U308, mount, and count.
Flame Correct
for Th234 (~ UX ) activity (see accompanying figure).
NoteB 1.
Liquid Br2 destroys NH20H and also the uranium-hydroxylamine
complex.
263
PROCEDURE 1 (Continued)
I
I
1
I
I
I
w
I
I
I
i
I
I
0 0 0 0 0 0 0 0
0 0
6
4
.
2
.
I
1.0 o
1 2
1
I
I
I
4
I
I
6
8
1
I
I
I
10
!2
I
14
DAYS CORRECTION FOR ON PLATE.
264
UXI ACTW’i TY\m~
Procedure
1.
U30e
PROOEDURE
2:
Purification of Urenlum-2400
Source: E. K. Hyde and M. H. Studier, ANL-4182 (1948). It$~&orâ&#x20AC;&#x2122;B note: The following procedure was used to formed.by the second order neutron capture of $381Qme prlnclpal decontaminating step Is the ether extraction if uranium from a reducing aqueoua solution. Uranium is further purified by a number of prec%pltaklons that are mt desoribed In detail. These, however, are fairly easy to perform. Irradiation and Ohemlcal Procedure Two grams of depleted uranium (1 pert &35 U238) as u308 in a mall
per 30,000
parts
26 alumtnum capsule was irradiated In
the Hanford pile for 12 hours Inaludlng time for Otartup and shutdown.
Six hours after the end of the Irradlatilon the cap-
sule end its contents were dhsolved
In nitric acid, using
mercuric ion as oatalyst for dissolving the aluminum.
The
uranium was extracted batchwise, the dissolved aluminum serving as a salting agent.
The ether containing the uranium was then
passed through two static wash columns packed with 3/32 Inuh stainless steel helices and filled with a solution 10~ in anrnonlum nitrate, 0.1 ~ in nitric acid, 0.01 ~ in ferrous ion and 0.1 ~ in urea.
Neptunium was reduced by the aluminum in
the dissolver and by the ferrous ion in the wash columns to an unextractable oxidation state (Np ~
and Np V).
Additional
ether was passed through the columns to strip out the uranium.
by remote control behind
These operations were carried out lead shielding.
The Initial dissolver solutlon measured roughly
50 roentgens per hour at 8 Inches.
The ether solution emerging
from the second column and containing the uranium measured only about 3 mr per hour at the surface~ and nxmt of this was ethersoluble iodine fission product activity.
The uranium was ex-
tracted from the ekher into an aqueous ammonium. sulfate solutlon and waehed several times with ether to remcve iodine activity.
LaF3 was precipitated from the uranyl nitrate solu-
tion after
reduction with sulfur
dioxide to remove any traces
of Np 239 which might have come through the ether extraction.
265
PROCEDURE 2 (Continued) * The uranium wae further purlfled by preoipltation as dluranate, sodium uranyl acetate, and peroxide and by a final ether exThroughout th10 final series of purlfLcatlonB there
traotfon.
was no detectable decrease In &activlty; the uranium was radloactlve~
this Indloates that
pure.
Small allquots of the final uranium solutlon were evaporated on platinum dlaoa and Ignited to U308 to Sbudy Ohanges in actlvlty.
The remalnlng uranium solution was used for extraction
of neptunium daughter fractions.
PROCEDURE 3! Source;
S.
Purlfloatlon
of Irradiated ~36.
F&led and H. Sellg, Private communication.
The present proaedure was used in an experiment mal neutron fission oross seotion :;’@gfd . ‘&~=’Jre e amount ‘he of ~q$ that oan be tolerated In such an experiment is very small.
Editor~s note:
Two oriterla were uBed in selecting the purification steps in the following procedure: 1)
To obtain uranium free of fission products and other extraneous aotivlties without Introducing contaminant ●
normal uranium in the procedure. 2)
The initial part should lend itself easily to remote control manipulation.
●The
reagents used were carefully purified. Thus, the nitric
acid and perchloric acid were redLstllled in a quartz still. The NH4N03 was prepared from gaseous ammonia and distilled HN03. The HC1 was prepared by passing HC1 gas into triply distilled SO,
etc.
266
PROCEDURE 3 (Continued) Procedure: Am
In Cave The irradiated urenium oxide (-.3
mg) was dissolved in
concentrated HN03 and made up to 2 ~ In HN03 with distilled ~0 to give total volume of about 15 ml. keep Pu and Np in +4 state.
Some FeH
The solution was saturated with
NH4N03 a,nd contacted four thes
with 10 ml portions of ether.
Each contact was scrubbed twice with 2 ~HN03 NH4N03 .
was added to
saturated with
The oombined ether extraots were back extracted three
times with 5 ml partions of H20.
The’~0
strip was evaporated to
dryness and treated with HC1 to destroy NH4N03 cexrled over. B. Outside Cave The sample could”now be handled easily outside the cave with a mlnlmumzof shielding, most of the actilvlty being due to $37.
Amass
speatrometrlo analysls showed It contained 0.5
weight ~ of &37.
A fission oount showed that additional purl-
flc.ation wa~ necessary to remove Np 238 formed by (n,y) on NP 237 whloh had built up during irradiation. The sample was taken up In about 0.5 ml 6 ~HCl on a small Dowex-1 column and washed. 6 ~ HC1.
ad
The Np comes off In
Finally the uranium was eluted with 0.5 ~ HC1.
eluate was
put
The
evaporated to dryness and taken up In 0.2 ml of 5 ~
HC1, 0.1 ~ KI and 0.05 ~ N2H40H . 2HC1.
This was heated at 90”
for 2 minutes, diluted to 0.5 ~ In HC1 and 7?l!Aextracted twice for 15 minutes.
The original fraotion waa washed twtce with
benzene and evaporated to dryness. In order to clean up the uranium for a mass spectrometric analysis, it was aubJeoted to another ether extraotlon as In the first step. &mad
fu?terthe NH4N03 was destroyed the sample was
with HC104 to destroy any organlo residue from the ether
extraction. . 267
PROCEDURE 4:
Uranium and Plutonium Analysla
Source: B. F. Rider, J. L. Russell, Jr., D. W. H&rrla, J. P. Peterson, Jr., GEAP-3373 (196o). Samples of dlsaolved Irradiated fuel contain highly radioactive fission products.
For this reason, uranium and
plutonium are separated prior to analysis.
The following
Pro-
cedure gives a good yield together wtth a good decontamination factor. Reagents: 1.
Dfstllled cone. HN03.
2.
2 g HN03 - distilled oonc. HN03, double distilled H20.
3.
U-233 solutlon, standardized.
4.
PU-236 solution, standardized.
5.
KBro
6.
- Crystals, Reagent Grade. Low natural U blank. 3 8~NH4N03 in 2 ~HN03 - Place 200 ml dlstllled 16 ~ HNO
+ 100 ml double distilled ~0
in a large beaker.
NH3 gas through solution until basic to pH paper. off excess NH3 (solution neutral).
3
Bubble Boil
Transfer to mlxlng
cylinder, add 50 ml of distilled 16 ~ KN03, dilute to 400 ml.
Check density of solution
7.
Hexone - dlstllled.
8.
HC1 - C.P. reagent.
9.
lkJHNo3-
mw
(1.31
na*UrSl
U
t 0.01
at
20째C.).
blank.
dlstilled cono. HNO~, double dlstllled ~0.
10.
3@
11.
0.2 ~ T.T.A. in xylene - 4.44 ~_ T.T.A. dissolved In 100 ml
H202 - meets A.C.S. specification, low natural U blank.
dlstllled xylene. 12.
Xylene - dlstllled.
13.
Ether - distilled.
14.
0.05 ~HNo3
15.
H20 - double distilled.
- distilled cone. HNOs, double dlsttlled ~0.
Glassware: All glassware used is Pyrex which has been soaked overnight in
268
PROCEDURE 4 (Continued) 5C$%HN03 and rl.rmed with double distilled water. rinsed with 5@
HNO
3
Plpeta are
and double distilled water before uelng.
SeparatlGn and Decontarninatlon Procedure: 1.
Place the allquot for analyeis in a 15 ml cone and evaporate to about 1 ml.
Add a suitable U-233 and PU-236 spike, one
drop cone. nitric acid, and several KBrO
crystals. Allow 3 to stand for 1 hour to allow oxidation of Pu to PU02H.
2.
Add 1.5 ml 8 ~ NH4N03 in 2 ~ HN03, and evaporate to about 2 ml.
3.
Prepare 2 scrub solutions in separate 15 ml cones, oontalning 1 ml of 8 ~ NH4N03 in 2 ~ HN03 and about 10 mgs KBr03. Preoxidize about 10 ml hexone with 2 ml of 2 ~ HN03 and
4.
KBr03.
Keep covered until ready for use.
~tract
the U and Fu four times for five minutes with 2 ml
portions of hexone (methyl isobutyl ketone), adding 1 drop of 16 M HNO
to the original solution after eaoh extraction. 3 Scrub each extract in turn with the two solutions prepered in step 3.”
5.
StrLp the combined hexone extracts with five 2 ml portions ‘f %0”
Evaporate the combined aqueoua portions to drynese,
and HC1, take to dryness. Evaporate 3 to dryness with HN03 under a gentle stream of pure nitrogen
add a few drops of HNO
on a boiling water bath.
6.
Prepare 3 ml of 1 ~HN03
and 1 drop of 3@
H202, add 1 ml to
the Pu and U residue from step 5 and two 1 ml portions to separate 15 ml cones.
7.
Extract immediately the Pu 2 times for 20 min. with 2 ml portions of 0.2 &T.T.A.
(thenoyltrlfluoroacetone)
in ~lene.
Scrub each in turn with solutions prepared in step 6. the aqueous phase for uranium.
Combine the T.T.A. extracts
and add a few crystals of tri.chloroacetic acid.
269
Save
PROCEDURE q (Continued) 8.
Mount the oomblned T.T.A. extracte on a platlnum plate for alpha pulse analyslm.
9.
After pulse enalyala~ remove the Pu for mans analysis as follows:
Cover disc with HF.
a heat lamp. dryne~s.
Evaporate to dryness under
Again cover disc with RF and evaporate to
Cover dlOc with cono. HN03 and evaporate. tb dIYneSS.
Repeat 3 or 4 times.
Cover disc with cono. nltrio, re-
flux a few seconds, and transfer cone. 10.
with a plpet to a 15 ml
Repeat j or q times.
Evaporate the combined oonc.
HNO refluxes to dryneea. 3 Treat residue with aqua regia snd evaporate to dryness.
Evaporate to dryness with aonc. HN03 on a bolllng water bath several times.
Add 50 ~ of 0.01 ~ HN03 to the evapor-
ated semple and submit sample for mass speatrogrqphlc analysls. 11.
Wash the original 1 ~ HN03 uranium fraction (Step 7) with ~lene.
Add 1 drop of HN03 and 3 drops of -HC1 to the
washed 1 ~ HN03 and reflux for about one-half hour to destroy the organlo present.
Evaparate to drynes~, flame
gently to destroy organi.c”matter and dlBsolve the refli.due with 2 drops HN03 and evaporate to dryness o“na water bath. 12.
Pipette three 1 ml portions of 8 ~ NH4N03 ln”2”FJ HN03, dissolve the evaporated U fraotion in one 1 ml portion. Plaoe the other 2 portions in two 15 ml cones for scrub solutions.
13.
Extract the U with f’our2 ml portions of dlethyl ether, adding 100 k of cone. HN03 before each extraction. extract in turn with 2 scrub solutlona
14.
prepared in Step 12.
Evaporate the combined ether extrac?ta over 1 ml of ~0 a 15 ml cone.
15*
Sorub each
Add 3 drOpS Of
in
Evaporate to dryness. ‘C1 and 1 *op
‘f ’03’
270
and evaporate to dry-
PROCEDURE 1 (Continued)
nesO repeatedly until the organic is destyoyed. to expell ammanium salts. orate
Then dissolve In HN03
to dryness on a water bath.
Flame gently and evap.
Add 50 k of 0.05 ~ HNO
to the dry cone and submit sample for
mass
3
spectrographic
analysls. Plutonlum Calculation: To determine the amount of Pu In the original sample, It IS necessary to measure In a Friach chamber the alpha spectrum The ratio of Pu-239 and Pu-240
of the plate prepared in Step 8.
activity to PU-236 aotivity is calculated.
If the ratio is mul-
tiplied by the orlglnal activity of F-u-236added, the original activity of Pu-239 plus Pu-240 can be obtained.
From the mass
analysis a Pu-239 to Pu-240 atom ratio 1â&#x20AC;&#x153;sobtained.
The speci-
fic aotivlty of the mtiture is calculated from that of the individual Isotopes.
The Pu-239 plus PU-240 activity can be con-
verted to Pu-239 plus PU-240 weight by dividing thie activity by the speciflo activity of the mixture. Uranium Calculation: The ratio of the various U isotopes to U-233 from the mass spectrometer data is multiplied by the amount of U-233 spike originally added to the sample to obtain the amount of each uranium Isotope present in the original sample.
PROOEDURE 5: Spectrophotometric Extraction Methods Specifio
for Uranium. Source:
W. J. Maeck, G. L. Booman, M. C. Elliott, and J. E.
Rein, AnaLChem.
&
1130 (1959). Abstract
Uranium as tetrapropylemmonium uranyl trinitrate is quan271
PROCEDURE 5 (Continued) tltatlvely
Beparated from large quantltieO of’dlverBe lonB by
extraction into methyl isobutyl ketone (4-methyl-2-pentanone)
Milli-
from an acid-deficient aluminum nitrate Baltlng aolutlon.
gram levels are determined by a dlreot absorbance measurement of the trlnltrate aomplex In the Beparated organic phame at 452 nw.
.Mlerogram armmnts are determined by adding dibenzoyl-
methane (1,3-dlphepj?l-lP3-propanedione) In an ethyl alcoholpyridine mixture to the separated organla phase and measurl~g the absorbance of the chelate at 415 m.
The ooeff’lclent of
varlatlon Is les~ than 1$ at the 10-mg. and 25-Y levels. limit of sensitivity Is 0.8 y f’or
The
the dlbenzoylmethane method.
Apparatue and Re agents Absorbance measurements of the tetrapropylatmnonium uranyl trinltrate complex were made with a Cery Model 14 reaordlng spectrophotometer and l-cm. Corex oells.
ATeflon9x9x6
mm.
spaoer placed In the bottom of the cells permits absorbance measurenwrbs with 2 ml. of 6ample.
Absorbance meaaurementa of
the dlbenzoylmethane complex were made with a Beckman DU spectrophotometer and 5-cm. Corex cells. ExtractIons were rinde In 125 x 15 rmn. test tubes with polyethylene atopperB.
A mechanical extraction deylce~- waa
uBed for egltatlon. Reagent grade inorganic and Eaatman Kodak Co, White Label organic
chemicals
were used without purification.
water waB used throughout.
Dlatllled
The uranium solutions were prepared
by dlaaolving purified black oxide, u308s in a Eli&t nltrlc sold, and making to volume
eXceBS
or
with water.
The dlb.enzoylmethane reagent Is prepared by dissolving 0.1140 gram of’ dlbenzoylmethane In 500 ml. of a 5% solutlon (v./v.) of ethyl
aloohol In Pyrldine.
Salting and Scrub Solutions.
A. 0.005?j
272
Tetrapropylarmnonlum
PROCEDURE 5 (Continued) Nitrate, 1~ Aold-Def’iclent Salting Solutlon.
Place 1050 grams
of alumlnum nttrate nonahydrate In a 2-llter beaker and add water to a voIume of 85o ti.
Heat, and af’ter diBBolutton add
67.5 ml. of concentrated armnonlum hydroxide.
Stir for several
minutes until the hydroxide prealpttate dlmaolves. than 50°C.,add 10 ml. of l@
Cool to leBa
tetrapropylammonlum hydroxide,
and atlr until dlat301ved. Transfer
to a l-liter volumetric
flask and make to volume with water.
A preliminary extraction
with methyl iaobutyl ketone la suggested ho remove uranium aontamlnatlon In whlah caae tetrapropylammonlum hydroxtde will have to be re-added. B. 0.025~ Tetrapropylammonlum Salting Solution.
Nitrate, 1~ Acid-Deflolent
Same aa A exoept that 50 ml. of l@
tetra-
propylammonium hydroxide Is used. C. 0.25~
Tetrapropylelmnonium Nitrate, lx Acid-Deflolent Neutralize 100 ml. of l@
Salting Solutlon.
hydroxide to pH 7 with 5~nltrlc
sold.
tetrapropylamnonlum
Transfer to a large
evaporating dish and let stand until a thick crystal Blurry forms (which may take aa long as 4 daya).
Place 210 grama of
aluminum nitrate nonahydrate in a 400-ml. beaker and tranafer the tetrapropylaummnlum nitrate aryatala Into 20 ml. of water. 18o tio
the beaker with
Stir and add water to a volume of approximately
Add 13.5 ml. of concentrated amnmnium hydroxide and
, atlr until diaaolution ia aomplete (which may require hours ).
Transfer
to
a 200-ml.
several
volumetric flask and make to
volume with water. D. Scrub Solutlon for Dlbenzoylmethane Method. grams of aluminum nitrate nonahydrate, 33 gram
Add 940
of tartarlc acid,
31 grams of oxalic acid, and 64 grams of (ethylenedinltrllo)tetr~cetfc
acid to 100 ml. of water and 150 ml. of concentrated
ammonium’hydroxide.
Heat with atlrrlng until dlasolved.
273
cool,
PROCEDURE 5 (Continued) tranBfer to a l-liter volumetrto
filter,
volume with water.
fla~k, and make to
Remave uranium contamination by a methyl
fsobutyl ketone extraction. E. Special Solutions.
The following salting and sorub
solutlonO are used in the dlbenzoylmethane method for samples containing cerium(IV) or thorium. 1.
Prepare an aluminum nitrate saltlng solution aO A, but
omit the tetrapropyl-nium
20
hydroxide.
Prepsre a sarub solution by dissolving 154 grams of
ammonium acetate and 20 grams of the sodium salt of diethyldithiooarbamate in water to a volume of approximately 900 ml. Adjust to pH 7, filter, end make to a l-liter volume with water. 3.
Prepare a mercuric nitrate solution by dissolving 0.063
gram of mercuric nitrate in
90 ml. of ~_ nitric acid and making
to a 100-ml. volume with 1~ nitric acid. Procedures Milllgram Amounts of Uranium.
With aqueous samples of 0.5
ml. or leas and containing up â&#x20AC;&#x2DC;co2 meq. of acid, 0.5 to 12 mg. of uranium can be extracted from a salting solution which is 0.025~ in tetrapropylammonlum nitrate and ~
acid-deficient.
Samples of high acidity should be neutralized to less than 2 meq. of free acid, or a salting solution which iB 2X acid-deficient can be used for samples containing up to 6 meq. of acid. cerium(~)
If
and thorium are present, the absorbance from uranium
wI1l be ~imum
if the combined uranium,
thorium, and cer-
ium(IV) do not exceed 0.05 mmole in the sample aliquot.
Samples
that uontaln more than 0.05 mmole of combined uranium, cerlum(IV), and/or thorium oan be analyzed after dilution, provided the resulting sample aliquot contains more than 0.5 mg. of uranium.
If this oondition cannot be met, the 0.25~ tetrapro-
pylanmmnlum nitrate salting solution is used, which can acconnm-
274
PROCEDURE 5 (Continued)
date up to 0.5 mmole of combined uranium, cerium(Iâ&#x20AC;&#x2122;V), and thortum. ,Plpet a sample of 0.500 ml. or less, to
containing from 0.5
12 mg. of uranium, Into a test tube containing 4.0 ml. of
aaltlng solution B or C.
Add 2.0 ml. of methyl isobutyl ketone,
stopperJ and extract for 3 minutes. phaae separation.
Centrifuge to facilitate
Transfer as much as ~ssible
of the ergantc
phase with a mloropipet to a l-em. cell containing the Teflon Opacer.
Measure the absorbance at 452 mu again~t a blank pre-
pared by substituting 1~ nitric acid for the sample. Aqueous ssmple aliquots
Microgram Amounts of Uranium.
containing up to 2 mg. of uranium and as much as 8~ In acid can be quantitatively extracted from a salting solution 0.005~in tetrapropylammonium nitrates
.
Neutralize samples of higher
acidity to less than 8Y before extraction. SAMPLES WITHOUT CEBIUM(IV) AND THORITllL Pipet a sample of 0.500 ml.. or less, containing from 0.8 to 75 y of uranium, into a test tube containing 5.0 ml. of salting solutlon A. Add 2.0 ml. of methyl isobutyl ketone, stopper, and extraot for 3 minutes.
Centrifuge to facilitate phase separation.
Transfer
as much as possible of the organic phase to a test %ube containing 5.0 ml. of scrub solution D, stopper, and mix for 3 minuteB.
Centrifuge â&#x20AC;&#x2DC;tofacilitate phase separation.
Remove
a l.00-ml. aliquot of the organic phase and transfer to a 25ml. flask.
Add 15 ml. of the dlbenzoylmethane-pwidine
and thoroughly mix.
reagent
Allow to stand 15 minutes, tranafer to a
s-cm. Corex cell, and measure the absorbance at 415 mu oompared to a blank prepared by substituting lx nltrlc sold for the sample aliquot. CONTAINING SAMPLES or
CERIUM(IV) OR THORIUM.
Plpet a sample
0.500 ml. or less, containing from 0.8 to 75 y of uranium,
275
PROCEDURE 5 (Continued) Into a test tube containing 5.0 ml. of the salting 8olutlon E-1. Add 4.Oâ&#x20AC;&#x2122;ml. of methyl isobutyl ketone, Btopper, and extract for 3 minutes.
Centrifuge to facilitate phase separation.
!Rransfer
as much as poeslble of the organic phase to another tube containing 5.0 ml. of scrub solutlon E-2, .stopper, and mix for 20 minutes.
Centrifuge as before.
Transfer ah least 3 ml. of the
organic phase to a test tube containing 5.0 ml. of salting soluAdd 0.5 ml. of scrub solution E-3, stopperj mix for
tlon E-1.
10 minutes, and centrifuge.
Remove a 2.00-ml. aliquot of the
organio phase and transfer to a 25-ml. flask. dlbenzoylmethane-pyrldlne
Add 15 ml. of the
reagent and thoroughly mix.
Let stand
15 minutes, transfer to a 5.O-cm. Corex cell, and measure the absorbance at 415 mu compared to a blank prepsxed by substituting 1.N. nitric acid for the sample allquot. Callbratlon.
Two dlfiâ&#x20AC;&#x2122;erent standards containing levels of
uranium equivalent to approximately 0.1 and 0.7 absorbance are procesBed.
The concentration of samples is established by the
average abBorptlvlty of these standardB provided agreement within statistical llmlts (95% confidence level) is obtained.
~
W. J. Maeck, G. L. Baoman, M. C. Elliott, J. E. Rein, Anal.
Chem. ~,
1902 (1958).
PRommm
6:
Determination of Uranium in Uranium Concentrates.
Source : R. J. Guest and J. B. Zimmerman, Anal. Chem. ~,
931 (1955).
Abstract A method Is described for the determination or uranium in high grade uranium materfal.
Uranium Is Beparated from contaminants by means
of an ethyl acetate extraction using aluminum nitrate as a salting agent.
After the uranium,has been stripped from the ethyl acetate
276
PROCEDURE 6 (Continued)
layer by means of water, colorlmetrlc determination of the uranium Is carried out by the sodium hydroxide-hydrogen
peroxide method.
The procedure Is acourate# rapid, and easily adaptable to routine work. ReaEents end Apparatus Reagente.
Ethyl acetate (Merck, reagent grade).
ALUMINUM NITRATE SALTING SOLUTION.
Place approximately 450
grams of reagent grade (Mallinckrodt) aluminum-nitrate 9~01
[A1(N03)39
in a 600-mI. beaker and add 25 to 50 ml. of dlOtilled water.
Cover the beaker and heat the mixture on a hot plate.
If a clear
solutlon does not result after 5 to 10 minutes of botllng, add 20 Repeat
ml. of water, and continue the boillng for 5 tire minutes. this step until a clear solution iB obtained after boiling.
Remove
the cover glass and concentrate the solution by boillng until a bolllng point of 130”C. Is reached. glass and either
Cover the beaker with a watch
transfer the solutlon to a oonstant temperature
apparatus or keep the boiling before use.
solution warm, finally heattng to just under If the solutlon Is allowed to cool to approxi-
mately 600C.$ rec~stalllzatlon
of aluminum nitrate will take plaoe.
It is necessary, therefore, to dilute the saltlng agent solutlon by about one third in order to prevent recrystallization tlon cools to room temperature.
If the solu-
Aocordlngly, If the S;lutlon 18 to
stand overnight, add 35 ml. of dlstllled water per 100 ml. of salting agent solution, mix well, and cover. If the salting agent solutlon Is.to be stored, the following procedure has been found convenient. proper concentration
Adjust the solution to the
(boiling point, 130”C.) and transfer to a 100-
ml. three-necked reaction flask set on a heating mantle. heating so that the temperature of the SOIUtlOI) 11O”C.
16
Ad~ust the
kept at about
In one of the necks place a water condenser”, In another neck
a thermometers and In the third neck a renmvable ground-glass stop277
PROCEDURE, 6 (Continued) per.
ThlH third neok Is utlllzed for
plpettlng the 6alting agent
solution. ALUMINUM NITRATE WASH SOLUTION.
Add 100 ml. of alumtnum nitrate
salting soltition (boiling point, 130â&#x20AC;?C.) to 73 ml. ofâ&#x20AC;&#x2122;@istllled water and 4 ml. of oonoentrated Apparatus.
nltrio
acid.
Beckman DU speotrophotometer.
Heating mantle. Three-necked reaction flask (1000 ml.). Water condenser. No. O rubber stoppers. Boil twice In ethyl acetate before use. Sixty-milliliter
separator
funnels (Squibb, pear-shaped).
Procedure
S3mple Dis~olution.
Place an appropriate quantity (1 to
5 grams) of the sample in a tared weighing bottle, stopper the bottle, and weigh the bottle and oontents Immediately.
Carry
out a moisture determlnatton on a separate sample if uranium Is to be calculated on a dry weight baals. Bring the sample into Bolution in one of three ways: (1) nitric aoid treatment, (2) multiacid treatment, or (3) sugar carbon-flodium peroxide fusion. For the nitric acid treatment, dlesolve the sample in a suitable quantity of nitric acid and transfer the solution and insoluble residue into an appropriate volumetric flask and make up to volume.
Regulate the dilutlon so that the aliquot chosen
for extraction will contain between 10 and 30 mg. of uranium oxide if the final dllutlon for the colorlmetric finish is to be 250 ml.
AdJust the acldlty of the sample solution
to
about
5$ in nitric acid. If nitric acid treatment la not suffloient, treat the sample with hydrochloric acid, nttrlc acid, perchlorlc acid, and finally sulfurlc acid.
If necessary, add a few milliliters 278
PROCEDURE 6 (Continued) of hydrofluoric acid.
Fume the sample to dryness and leach
the residue with nitrlo acid, ftnally transferring the solution and residue to an appropriate volumetric flask and ad~ustlng to 5$ In nltrtc acid as In the single acid treatment. If the sample is refractory, use the sugar carbon-sodium peroxide fusion method descrfbed by Muehlberg%
titer
dissolu-
tion of the sample In this manner, transfer the acldlfled solutlon to an appropriate volumetric flask and dilute so that the final solution la 5$ In nitric acid. Allquot solution sampleB dfrectly or dtlute as required for an &hyl
If the sample iflallquoted d~k
acetate extraction.
reclilyfor an extraction, add 5 drops of concentrated nitric
acid
per 5-ti aliquot of sample and standards before extraction. Where samples are diluted before allquots are taken for extraction, adjust the actdity so that the ftnsl volume Is 5$ in nltrlc acid. Ethyl Acetate Extraction.
Place an appropriate allquot
(usually 5 ml.) in a 60-ti. separator
funnel, the Btopcock of
which has been lubricated with slltcone grease.
Add, by means
of a graduated pipet, 6.5 ml. of aluminum nitrate solution per 5 ml. of sample solution.
The aluminum nitrate salting solu-
tion should be added while hot (above 11Oâ&#x20AC;?C.).
CoOl the solu-
tton to room temperature and add 20 ml. of ethyl acetate. Stopper the separator
funnels with pretreated rubber stopper~.
Sneke the mixture for 45 to 60 seconds.
Occasionally crystuli-
â&#x20AC;&#x153;zation will take place In the separator
finnel near the stop-
cock.
In such a case place the lower part of the separator
funnel in a beaker of hot water until the flolldlfled portion dissolves. After the layers have separated, drain off the aqueous (lower) layer.
Occasionally a cloudiness will appear at the
boundary of the aqueous and organic layer. should not be drained off.
This cloudy portion
Add 10 ml. of alumlnum nitrate wa8h 279
PROCEDURE 6 (Continued) solution to the fâ&#x20AC;&#x2122;unnel and again shake the â?&#x2018;titure for 45 to 60 secondB.
Drain off the aqueouB layer, once again being careful
to retain the cloudy portion at the boundary in the funnel. Rinse Inside the stem of the separator
funnel with a Btream of
wa%er from a wash bottle. Water StrippLng of Uranium from Ethyl Aoetate Layer Followed by Sodium Hydroxide-Hy drogen Peroxide Colorfmetrlc Finish. Add 15ml.
of water to the separator
funnel containing the ethyl
auetate, stopper the flask, and shake the mixture for about 1 minute.
After washing off the stopper with water, drain the
aqueoufl layer Into a volumetric flask of suitable size and wash the fleparatory funnel and ethyl acetate layer 4 or 5 times with 5-ml. portion~ of water by means of a wash bottle.
Combine the
aqueous fracticum. Add enough 2C@ sodium hydroxfde solutlon (w./v.) to neutralize the solution and dissolve any precipitated aluminum hydroxide, then add 10 ml. In excess per 100 ml. of final volume.
Add 1 ml. of 3@
hydrogen peroxide per 100 ml. of final
volume and make up the volume to the mark with distilled water. Read the absorbance after 20 minutes on the Beckman DU spectrophotometer at 370 mp against a reagent blank, using l-cm. Corex cells and a slit width of 0.2 mm.
Compare the ab~orbances of
the samples against the absorbance
of standard uranium solu-
tions which have been carried through the procedure at the same time.
Choose the standards so that they cover the range into
whioh the samples are expected to fall, using a ratio of one standard to six samples.
In practice it Is oustomary to work
between the limite of 10 and 30 mg. of uranium oxide.
This is
arranged by estimating the required sample weights and diluting and sampling accordingly.
The final volume for calorimetric
reading is usually P50 ml.
280
PROCEDURE 6 (Continued) Double EWraction
of Uranium with Ethyl Acetate Followed
by Applioatton of Differential Colorlmetry.
Uranium determina-
tions requiring the highest accuracy may be carried out
by a
double extraction of uranium with ethyl aaetate followed by the application of differential colorlmetry as de~ortbed by Hlskey and others.=
In suah a case it I.Brecommended that between
100 and 150 mg. of uranium oxide be extracted, and a wave length of 400 w
be uBed during the colorlmetrlc flntsh.
The procedure
described below has been found satisfactory. Extract an appropriate aliquot of the sample solution with
20 ml. of ethyl acetate as described above. queous layer into a second separator
Draw off the a-
funnel containing 10 ml.
of ethyl acetate.
Stopper the funnels and shake the mixture for
45 to 60 seaonds.
Drain off and discsrd the aqueous layer.
Add
10 ml. of aluminum nitrate wash solutlon to the first ethyl aaetate extract, stopper, and shake the mtiture for 45 to 60 seconds. Drain off the aqueous layer into the separator
funnel containing
the second ethyl acetate extract, stopper, and shake the mtiture ~or 45 to 60 seconds.
Drain off and discard the aqueous layer.
Combine the ethyl aoetate fraotlons. tor
Rinse the seoond separa-
funnel with 20 ml. of water, draining the washings Into the
separator tions.
funnel containing the combined ethyl acetate frac-
Shake the mixture for 1 minute.
Continue the water
stripping as described above, collecting the fractions in an appropriate volumetric flask.
Flnlsh calorimetrically as de-
scribed previously, allowlng the strongly colored solution to stand 1 to 2 hours to ensure stabillty before reading as a fading effect of about 0.005 absorbance (optical density) has sometimes been noted on freshly prepsred samples. Read the absorbance of the sample solution on the Beckman DU spectrophotometer at 400 mp against a reference Solutlon
281
PROCEDURE 6 (Continued) which contalnm a known amount of uranium and has been carried through the extraction and color development procedure In the same manner as the sample.
Also oarry along other standards
aontalnlng slightly higher and lower amounts of uranium the sample.
than
Determine the concentration of uranium In the
ssmple either by the callbratlon+urve method, aa described by Neal%
method or the correotlon
If the amount of uranium In the
sample Is not known, make a test run by taking an aliquot of the sample solution and assaying for uranium by the more rapid single extraction method.
The 8tandard solutions to be used oan
then be chosen according to the result obtained. Removal of Interfering Thorium. traction, strip the uranium In water
After an ethyl acetate exfrom the ethyl acetate and
collect the uranium fraction In a 250-ml. beaker. 2@
Add enough
(w./v.) ~odlum hydroxide solution to neutralize the solution
and redissolve precipitated alumlnum hydroxide. ml. excess of 2@
Then
add 10-
sodium hydroxide solution and 1 ml. of 3@
hydrogen peroxide per 100 ml. of ftnal volume. tfon through an n-cm.
Filter the solu-
41H filter paper (Whatman), collecting
the filtrate in a volumetric flask of suitable sl.ze. Wash the paper and preolpltate once with 5 ml. of a solutlon of @ hydroxide containing 0.1 ml. or #
hydrogen peroxide.
sodtum
Re-
dissolve the precipitate by washing the paper with 10 ml. of lQ% nltrtc acid solutlon, colleotlng the washings In the original beaker.
Neutralize the solutlon with 2@
solution, and add 2 ml. In excess.
sodium hydroxide
Add 0.5 ml. Of 3@
~tiO-
gen peroxide, and filter off the prealpltate on the original filter paper, washing as before end colleotlng the filtrates In the original volumetric flask.
If the precipitate on the
paper Ls colored yellow, repeat thie step.
Make the solution
In the volumetrto flask up to volume and read the absorbance
282
PROCEDURE 6 (Continued) on the 6pectrophotometer.
Carry standards through the same
procedure ae the flamplefl.
SW.
L. ?luehlberg, Ind. Eng. Chem.
l&
690 (1925).
PC.
F. Hlskey, Anal. Chem. 21, 1440 (1949).
~ C. F. Hlskey, J. Rabinowltz, and I. G. Young, Anal. Chem. ~
1464 (1950).
~G.
W. C. Mllner and A. A. Smalea, Anal.yat~
SW.
T. L. Neal, Analyat Q,
403 (1954).
~ I. G. Young, C. F. Hlakey, Anal. Chem. ~,
~OCEDURE 7: Source:
414 (1954).
506 (1951).
Uranium-237.
B. Warren,
LA-1721 (RW) (1956). 1. Introduction
In the carrier-~ree method for the determination of $37, the principal decontamination step (which i.apreoeded by a Ia(OH)3 aoavenge and partial removal ofâ&#x20AC;&#x2122;plutonlum a~ the cupferron complex) is the extraction of uranium Into 3@ (tertiary butyl phosphate) in benzene.
TBP
Addltlonal decontsm-
Ination la effected by adsorption of uranium, flrat on an anion and then on a cation exchange realn. electroplated on platinum.
The uranium Is finally
The chemical yield is 40 to 6*
end la determined through the use of $33
tracer.
The T337
IS p-counted in a proportional counter wtth a 2.61-mg/cm2 Al abaorber, end from the number of counts the number of atoms of the Isotope Is calculated.
Four samples can be run In
about 6 hours.
283
PROCEDURE 7 (Continued) 2. $33
Reagents the a-counting technique
tracer: amount determlnedby
employed La carrier: 10 mg La/ml [added as LS(N03)3
●
6H201
Fe carrier: 10 mg Fe/ml [added as Fe(N03)3 . 9~0
in very
dilute HN031 HC1: O.1~ HC1: 5~ HC1: 10~ HC1: cone. HN03: ~ HNo j: 5g KNo : cono. 3 NH40H: oonc. NH20H . HCII 5~ (NH4)2C204 in ~0:
4S
TBP (terlary butyl phosphate): 3@
by volume In benzene (Note 1)
AqueouO cupferron reagent; @ Methyl red Indicator solution:, O.1~ tn Methanol: anhydrous Chloroform NH “ gas 3“ Cla: gaa . Equipment Centrifuge Fieher burner Block for holding centrifuge tubes Pt-tipped tweezers Steam bath 5-ml Byringe and transfer RipetO Mounting plates
284
9@ ethanol
PROCEDURE 7 (Continued) 40-ml centrifuge tubeH: Pyrex 8140 (three per aliquot of sample) Ion exchange oolumne: 8 om x 3 mm tubing attaohed to bottom of 15-ml centrifuge tube AnIon reeln: 5 cmDowex Cation resin: 5 omDowex
w-x8,
400 mesh, (Note 2)
50-x8, 100 to 200 mesh, (Note 2)
Stirring rode Motor-driven gl&Bs stirrers Platlng set-up: same as that used in Procedure 1 except that the Pt cathode la a 1“ dlak and the glase ohlmney has a 7/8” Id. 4. Procedure To an aliquot of sample not exceeding 20 ml In
w“
a 40-ml centrifuge tube, add 1 ml of &33 of La carrier, and bubble In NH which forms coagulates.
3
traaer and 3 drops
gae unttl the preoipltate
Digest for 15 mln on a steam bath,
oentrifuge~ and dlecard the aupernate. D1.snolve the preotpltate In 0.6 ml of cone. HC1
Step 2.
and dilute to 10 ml with ~0.
Add 5 ~ops
and 2 drops of Fe carrier (if thlB
element
sent)~ end allow to stand for 10 min. 6 ml of @
of 53 NH20H “ HC1 Is
not
already
pre-
Add 4 ml of chloroform,
oupferron, and extract the Pu(17J)-oupferron,complex
by stirring for 2 min.
Remove the chloroform layer by meane
of a transfer pipet and discard.
Extract the aqueous phaBe,
three additional times with chloroform. add 3 drops of
La
To the aqueous layer
osrrler and bubble In NH3 gas until the pre-
clpttate formed coagulate.
Dlgeat for 15 mln on a steam bath,
aentrlfuge~ and discard the supernate. ~
Dissolve the ~eelpltate
dilute to 5 ml with ~0, for 2 min.
,,
In l“6fi
of’ ~ono” ~03#
add 2 ml of TBP solution, and etlr
Draw off the TBP layer
and tranefer to a clean 40-
285
PROCEDURE 7 (Continued)
ml centrifuge tube.
Extract again with 2 ml of TBP solution
and combine with the previous extract.
Add 1 ml of TBP solu-
tlon to the orlgimal tube, draw it aff, and combine with the other extracts. Step 4.
Wash the TBP extracts with two 3-ml portions
5~ HN03, discarding the washings.
of
Bubble In C12 gas for 5 min
at a vigorous rate. SteP5.
Transfer the solution to aDowex
A2 anion ex.
Permit one-half of the solution to pass through
change oolumn.
the resin under 8 to 10 lb presBure.
Add 1 ml of cons. HC1 to
the column and allow the remainder of the Boltitlon to pass through under pressure.
Wash the column twice with 2-1/2 ml
of 10~ HC1 and then tvrloewith 5~ HC1, discarding the washings. Elute the U with two 2-1/2-ml portions of O.l~HCl,
catohlng
the eluate In a clean 40-ml centrifuge tube. Step 6.
Dilute the eluate to 10 ml with SO
and pass
through a Dowex 50 aatlon exchange column under 1 to 2 lb presmre.
Waah the resin three times with 2-1/2-ml portions
of O.1~ HC1 and discard the washings. 2-1/2-ml portions oi’~ w“
Add 5 d
Elute the U with two
HN03 into the plating cell. Of 4X (NH4)2C204, 3 dI’OPS Of methyl
red Indicator t301utlon, and make baBlc by the dropwise addition of cone. NH40H.
Make the solution just red to the indicator
by the dropwise addition of 6~ HN03, and add 3 drops in excess.
Plate at 1.1 amp and 8 volts for 1* hr at 80*c. At the
end of the first 10 mln, add 3 drops of methyl red solution and make ac,idwith 6~ HIJ03. Check acidity at two additional 10-min intervals, and at the end of AO min add 3 drops of cone. NH OH. At 10-min intervalB thereafter check to see that 4 the plating solution Is just basic to the indicator. Remove the cell from the water bath, waah three times with methanol,
286
PROCEDURE 7 (Continued) and dismantle the cell , carefully keeping the Pt disk flat. Flame the disk over a burner. f3-count In a pro~rtlonal
a-count the @33,
mount, and
counter with a 2.61-mg/cm2 Al ab.
sorber. Notes The TBP Is purlfled before use by waBhlng flrsb with
1.
1~ NaOH and then with 5~ HN03. 2.
Before use, both the anion and cation resin are
washed alternately at least five times each with ~0 and are then stored” in 3. per W
and HC1,
I-$o.
See Procedure 1 for the correction for U3$ activity
U3°8 on plate.
PROCEDURE8: Radioassay of Uranium and Plutonlum In Vegetation, Soil and Water. Source:
E. L. Geiger, Health Phyeics ~, 405 (1959). Abetract
A method ie discussed for the separation of uranium and plutonium from vegetation, soil and water.
The method
1s baeed on the extraction of uranium and plutonium from 4 to 6 N nttric acid Into 5@ decane dlluent.
trl-n-butyl phosphate in n-tetra-
Uranium and plutonium are recovered together
with sufficient reduction In total solids to allow a-counting and pulse height analysis.
Data from several htindred ‘spikedm
samples to which uranium and plutonium were added Indicate a nesxly equal recovery of uranium and plutonium.
Average re-
coveries are 76 t 14 per cent for vegetation, 76 k 16 per cent for soIl, and 82 * 15 per cent for water.
The procedure
Is designed for samples that may be collected and analyzed
287
PROCEDURE 8 (Continued) for radloactlvlty as a part of a health physics ?eglonal monitoring program. Procedures Preparation of senples Vegetation.
Cut oven-dried vegetation Into small piecee
and weigh 10.O.g Into a 150 ml be-er.
Heat the sample at
600”c, starting with a cold muffle furnace.
When only white
aeh remalne, remove the beaker from the muffle furnace and allow to cool.
Carefully add 2 ml of’water, then add 10 ml
) solution. Cover the beaker with 33 a watch glaOs and boil the solutlon for 5 min. Allow to COO1, of 83
HN03-0.5 ~Al(NO
add 1 ml of 2 ~KN02
Solution and transfer the sample to a
100 ml centrifuge tube.
Uee 4 ~ HN03 to complete the transfer.
Centrifuge and decant the supernate into a 125 ml oyllndrlcal sep&ratory funnel graduated at 30 ml.
Wash the residue with
centrifuge, and decant the wash Oolution to the 4 ‘m03’ seperatory funnel. The acid normallty of the oombined solutlons at this point Ie 4-6 ~end exceed 29 ml. soil.
the total volume should not
Proceed to the extraction procedure.
Grind 5 g of oven-dried soil with a mortar end
pestle until the entire eample oan pass throu~ sieve.
a 200-mesh
Weigh 1.0 g of the 200-mesh soil into a 50 ml platinum
crucible and heat the sample at 6000C for 4 hr.
Reinove the
sample from the muf~le furnace and allow to cool.
Add 3 ml of
i’@ HN03 and 10 ml of ~
HF then stir the sample for G-3
mln with a platlnum rod.
Heat the sample in a 200”C sand
bath until
all tracee of moisture are removed.
Repeat this
HN03-HF treatment being careful that the sample is completely dry before proceeding to the next step.
Allow the Bample to
cool and then add 15 ml of 6 ~ HN03-0.25 l!. A3(N03)3 solution. Cover with a watch glass and heat In the sand bath for 5 min.
288
PROCEDURE 8 (Continued)
Allow to cool and decant the solutlon through a filter, mch as Whatman no. 40, into a 125 ml cylindrical aep=atory graduated at 30 ml.
Leave aB much of the reOidue as possible
in the oruoible and repeat the hot 6~~03-0.25 Allow to cool and then filter.
treatment.
funnel
k&ll(N03)3
Proceed to the ex-
traction procedure. Water.
Place 1 1. of the sample In a 1.5 1. beaker and if Add 15 ml of 7C@ HN03 and
basic, neutralize with nitrio acid. evaporate to 30-40 ml.
Deoant the solution through a filter,
such 8B Whatman no. 40$ Into
Wash the 1.5 1.
a 100 ml beaker.
beaker, the residue and the filter with 42
HN03.
Evaporate the Add20m10f4~
combined solution In the 100 ml beaker to 5 ml.
cover with a watch glass, and heat for 5 min. !I!ranaferthe â&#x20AC;&#x2122;03â&#x20AC;&#x2122; sample to a 125 ml cylindrical separator funnel graduated at 30 ml.
Wash the beaker with 4 ~HN03
and transfer to the seperatory
funnel, being careful that the total volume in the separator funnel does not exceed 29 ml.
Proceed to the extraction procedure.
Extraction Add l.ml of 2 M.KN02 to the senple in aeperatory funnel.
the 125 ml cylindrical
Dilute to the 30 ml mark with 4 ~HN03
stir the aolutton briefly.
Add 30 ml of 5@
and
TBP In n-tetradecane.
Agitate the solution vigorously for 4 mln with an air-driven Ettrrer.
Discard the acid portion (lower layer).
portion with 4 ~HN03
Wash the TBP
and again dtscard the acid portion.
Back
extract with seven 15 ml portions of distilled water, collecting the strip solution In a 150 ml beaker.
Evaporate the combined
aqueous portions to 10-15 ml., then quantitatively transfer the solution to a flamed stalnlesO steel planchet.
Allow to dry under
a heali lamp, flame the planchet to burn off organtc residue, and count on an a-oounter.
Retain for pulse-height analyals if the
a-count exceed~ a epeclfied level.
289
PRomoum
9: Separation of Uranium by Solvent Extraction with
Trl-n-octylphosphine Source:
Oxide.
C. A. Horton and J. C. White, Anal. Chem. ~,
1779 (1958).
Abetract A simple, rapid method for the determination of uranium Ln Impure aqueou8 solutions wafl developed. by O.1~ trl-n-ocmlphosphlne acid solution.
Uranium(VI) Is extraoted
oxide in cyclohexane from a nitric
A yellow oolor Is formed h
an aliquot df the or-
ganic extraot by addition of dlbenzoylmethane and pyrldtne In ethyl alcohol.
Interference by cations 1s minimized or elltinated by
selective reduation, by fluortde oomplexatlon, or by absorbance measurement at 416 my rather than 405 WO maximum absorbance?
the wave length of
Interference by excess fluoride or phosphate
la eliminated by addition of aluminum nitrate before extraction. The range of the method Is 20 to 3000 Y of uranium In the original solution, and the standaxd devlatlon is *2%. Apparatus and Reagents Absorbance measurements were made with a Beckman DU spectrophotometer, using l.00-om. Corex or silica cells. Phase equlllbratlon for most extractions was o.errted out in the bottom portion of the apparatus (see accompanying figure). Phase separation and removal of allquots of the upper organic phase occurred after inverting the apparatus so that the solutlon was In the portion of this apparatus shown on top in the figure. Some extractions were carried out in 60- or 125-ml. separator STANDARD UR.ANIUM SOLUTIONS. uranium
funnels.
A stock solutlon of 24.0 mg. of
per ml. was prepared by heating 7.10 gram of uranium
(IV-VI) oxide (u308)# prepared from pure uranlum(VI) oxide (U03), In 10 ml. of perchloric acid to dissolve It, and then dllutlng the resultant solutlon to 250 ml. with water. solutlon were made as required.
Dilutlona of this
Another standard solution in
sulfuric acid was also used In checking the ~pectrophotometrlc calibration curve. 290
5%
PROCEDURE 9 (Continued) DIBEN’ZOYIMETHANE. dlbenzoylmethane
A solution that contained 1 gram of
(l,s-dlphenyl-l,s-propanedione),
obtained from
Eastman Kodak Co., In 100 ml. of 95% ethyl alcohol was prepared for use as the chromogenic agent. PYRIDINE.
For most of the work, a solutlon prepared by
mtilng 1 volume of redistilled reagent grade pyridlne and 1 volume of 95$ ethyl alcohol was used. TRI-n-OCTYLPHOSPHINE
OX~E.
A O.10~ solutlon of this material,
prepared In the authors’ laboratory, in cyclohexane, Eastman 702 or 702S, was used.
This phosphlne oxide Is now available commer-
cially from Eastman (EK 7440). Sodium bi.sulflte, 10 (w./v.) ~ In water, stored at about 10”C. Hydroxylamine sulfate, 2~ In water. Potassium fluorlde, 1~ In water, stored In a polyethylene bottle. Procedure Preliminary TheRt.menk& fering ions.
Samples which do not contain inter-
ptpet a 0.5- to 8-ncL. aliquot of a solutton In n~tric,
perchlorlc,, or sulfuric acid, esthnated to contain 15 to 2sO0 of uranium,
y
into the bottom portion of the extraction vessel.
By the addltlon of strong 10~ sodium hydroxide, nitric acid, or sodium nitrate, adjust the solution so that a total aqueous volume of 10 ml. will be 1 to 32 In hydrogen ion end 2 to 4~ in nitrate ion.
For almost neutral solutions, 2 ml. of concentrated nitric
acid will give the correct concentrations for a 10-ml. aqueous Volume o
Adjust the total volume to 10 ml.
Up to 12 ml. of aqueous
solution can be shaken with 5 or 10 ml. of extractant paratus without undue splashlng.
In the ap-
If the total aqueous volume IS
greater than 12 ml. after adsusting the acidity and nitrate content, perform the extraction In a separator special extraction vessel.
291
funnel instead of the
PROCEDURE 9 (Continued) B.
Samples containing Iron(III), chromium,
dium(V).
or vana-
Plpet a 0.5- to 6-ml. allquot of a solution In dilute
perchloric or sulfuric medium, estinmted to contain 15 to 2500 â&#x20AC;&#x2DC;y of uranium,
Into the bottom portion or the extraction vessel.
Reduce the Iron(III) to iron(II), the dromlum(VI)
to chromlum(III),
and the vanadium(V) to vanadlum(TV or III) without reducing the uranium
to uranium.
Sodium blsulflte la a satisfactory
reductant If the solutlons are boiled to remove excess sulfur dloxlde.
HydroWlamlne
sulfate Is also a satisfactory reductant,
but amalgamated zinc is unsuitable.
Add sufficient nitrtc sold or
sodium nitrate and water so that the final aqueouB vblume 12 ml. will be 1 to ~ c.
of 8 to
in hydrogen ion and 2 to 4! in nitrate ion.
Samples containing titanium, thorium, hafnium, zirconium,
or iron(III), but only traces of alumlnum.
PiPet a 0.5- to 6-ml.
aliquot of a solution In dilute nitriaP perchloric, or sulfurlo acid, estimated to contain 15 to 2500 y of uranium, Into the bottom of an extraction vessel.
Add sufficient base or said, nitrate,
and water to give a volume of about 8 ml., such that the solutlon IS 1 to 3~ In hydrogen
ion
a maximum of 2.5 ml. of ~
and 2 to 4~ in nitrate Ions. potassium
Add Up to
fluoride when the concentra-
tions of Interfering Ions sre unknown.
If high concentrations of
these Ions are known to be present, additional fluoride can be tolerated. D.
Samples containing excessive fluorlde or phosphate.
Pipet an allquot Into an extraction vessel, and adjust the aald and nitrate contents as in !llreat~nt C.
Add sufficient alumtnum
nitrate to complex the fluorlde and phosphate estimated to be present.
The total volume should be 12 ml. or
less.
FLxtractlon. For amounts of uranium estimated to be under about 1400 â&#x20AC;&#x2DC;y, plpet 5 ml..of O.1~ tri-n-octylphosphine cyclohexane
oxide in
Into the extraction vessel oontalnlng the treated
2$)2
PROCEDURE 9 (Continued) sample.
For 1400 to 3000 â&#x20AC;&#x2DC;y of uranium, use
10 ml.
of extractant.
Attach the top of the vessel and shake for 10 minutes on a reciprocating shaker.
Invert the extraotlon apparatus for separa-
tion of the phases and removal of allquots of the upper organlo phase.
14mm. l+ . .
T
EXTRACTION USED Color Devel opment.
IN
APPARATUS Procedure
9.
Transfer by plpet a 1-, 2-, or 3-ml.
aliquot of the organic extract Into a 10- or 25-ml. volumetrlo flask such that the final solution will contain between 0.5 and
10 â&#x20AC;&#x2DC;yof uranium per ml.
For 10-rnl.volumes, add 1.0 ml. of 5@ 293
PROCEDURE 9 (Continued) pyrldlne in ethyl alcohol, 2 ml. of 1% (w./v.) $ dlbenzoylmethane In ethyl alcohol, and 95$ ethyl alcohol to volume.
For
25-d.
volumes, use 2.5 ml. of pyridine and 5 ml. of dlbenzoylmethane. After 5 or more minutes , measure the absorbance at 405 w cells, using
95$
In l-cm.
ethyl alcohol as a reference solution.
For ssm-
ples recelvlng lkreatment C, also measure the absorbance at 416 mu. A blank should be carried. through the entire procedure dally. Calculate the uranium content using the factors obtained by extracting standard pure uranium solutlons as directed in !lYeatment A, and measured at both 405 and 416 W.
PROCEDURE 10: Radlochemlcal Determination of Uranium-237. Source: F. L. Moore and S. A. Reynolds, Anal. Ghem. &
108o (1959).
AbOtract A radloohemlcal method for the determination of uranium-237 Is based on complexlng the uranyl Ion in alkallne solution with hydroxylemlne hydrochloride, followed by scavenging with zirconium hydroxide end extraction of the uranium from hydrochloric aoid solutlon with trliaooctylamlne-xylene.
The technique has been
applied successfully ta the determination of uranium-237
In
homogeneous reactor fuel solutions. Preperatlon and Standardization of Uranium Carrier Weigh out approximately 50 grams
of
urenyl
nitrate hexahydrate.
Dissolve and make to 1 llter with 2 ~ n~trlc acid.
Standardize
the carrier by pipetting 5-ml. allquota into 50-ml. glass centrifuge cones and preclpltatlng ammonium diuranate by adding concentrated ammonium hydroxide.
Filter quantitatively through No. 42
Whatman f~.lter paper and ignite In porcelain crucibles at 800â&#x20AC;?c. for 30 minutes.
Wefgh as U308.
294
PROCEDURE 10 (Continued) Frocedure In a 40-IzI..tapered centrifuge tube add 1 ml. of uramlum” omier
and 0.2 ml. of zirconium oarrler (approximately 10 mg. “per
ml.. of zirconium) to a suitable allquot of the Bample solution. Dilute to approximately 10 ml., mix well , and preci.pltate annzonlum diuranate by the addition of concentrated amnonium hydroxide. Centrifuge for 2 minutes and dlOaard the aupernatant Oolutl.on. Wash the preaipltate once with 15 mls of ammonium hydroxide
(lto
1).
Dissolve the preclpl.tate In 1 to 2 ml. of concentrated hydrochloric acid solution, dilute to about 10 ml., add 1 ml. of hydroxylamine hydrochloride
(5 ~), and mix well.
Prealpitate
zirconium hydroxide by the addition of concentrated ammonium hydroxide.
Centri~ge
for 2 minutes, add 0.2 ml. of ziroonium
carrlerj and stir the supernatant solution, being careful not to dfsturb the precipitate.
Centrifuge for 2 minutes.
Add 0.2 ml.
of zirconium carrier and repeat. Transfer the supernatant solution to another qO-ml. centrifuge tube, add several drops of phenolphthalein$ and ad~ust the pH to approximately 8 by adding concentrated hydrochloric acid solution dropwise.
Add an equal volume of concentrated hydro-
chloric acid Oolution and extract for approximately 0.5 minute witha cmehalf volume portion of 5Z (w./v.) trilsooctylaminexylene.
Discard the aqueous phase.
Wash the organic phaBe by
mixing for 0.5 minute with an equal volume chloric acid solution.
portion of 5 ~ hydro-
Repeat the wash step.
Strip the uranium
from the organic phase by mixing thoroughly with an equal volume portion of 0.1 ~ hydrochloric said solution for 0.5 minute. Disoard the organic phase. Add 0.2 ml.. of zirconium carrier, mlx well, and repeat the above procedure, beginning with the preclpitatiori”of ammonium diuranate.
295
PROCEDURE 10 (Continued) Finally, precipitate ammonium diuranate by the addition of concentrated ammonium hydroxide. cant and discard the
Centrifuge for 2 minutes.
aupernatant Bolutlon.
De-
Filter on No. 42 What-
man filter paper and Ignite at 800”c. for 30 minuteO. Weigh
the uranlumoxide
on a tared aluminum foil (0.0009
Inch), fold, and place In a 10 x 75 nun. oulture tube. suitable oork and count the uranium-237 @mma well-type sclntlllatian counter.
Int9ert a
radioactivity In a
Count the same day of the laBt
ohemlcal Beparatlon. Apply a blank correction If very low urantum-237 levels are being determined.
Determine this correction by taking the same
allquot of uranium
carrier through the exact procedure de~crlbed
above.
The blank correction 18 due primarily to the gamma radLo-
activlty asaoclated with the uranium-235 In the uranium carrier.
PROCEDURE 11: Source:
Separation of Uranium and Bismuth.
A. I&lshen and H. Freiser, Anal. Chem. ~,
288 (1957).
Editorta note: Uranium has been Beparated from a sOOO-fold excees of bimuth by the following method. Uranium is, however, not completely extracted (only g8.4~ at pH values greater than 6.5). If this correction is applied, uranium Is quantitatively determined by polarographlc means within an experimental error of *1$. Reagents Acetylaaetone.
Commercial acetylacetone was purified by
the method described by Stelnbach and fielser.~ Procedure Analyels. The method of Souchay and Faucherre,~ using O.1~ ED’PA and 2~ sodium acetate as a aupportlng electrolyte, waa found to be Bultable In the presence of diaaolved acetylaaetone.
The
half-wave potential waa shifted to -0.47 volt but the wave height waa not affected.
296
‘
PROCEDURE 11 (Continued) Separation.
Solutlons of uranyl sulfate containing 0.1 and
1.0 mg. of uranium were retied with dtfferient amounts of bismuth trichloride aolutlon.
A solution of the disodium Oalt of EDTA was
added to give a bismuth to EDTA ratio of 1 to 30.
The pH of the
mixture was raised to 7.5 by careful addition of 1~ sodium hydroxide. .
Then approximately 10 ml. of acetylacetone was added and the tnixkureehaken
for 10 minutes.
The aoetylacetone phase was separated,
filtered, and made up to a volume of 10 ml., of which 2 ml. was withdrawn by a pipet into a 10-ml. borosilicate glass volumetric flask.
The flask was very gently warmed until the liquid was re-
duced in volume to about 0.5 ml.
Then the supporting electrolyte
was added and the reaulttng solutLon deaerated for 5 minutes in a 10-mL.
Lingane-Laitinen H-type polarographic electrolysis cell.
The polarogram was then recorded and the concentration of uranium found from suitable calibration curves. ~J.
F. Steinbach, H. Freiser, Anal. Chem. 26, 375 (1954).
~P.
Souchay, J. Faucherre, Anal. Chlm. Acta&
PROCEDURE 12:
252 (1949).
Isolation and Measurement of Uranium at the
Microgram Level. Source: C. L. Rulfs, A. K. De, and P. J. Elving, Anal. Chem. ~,
I-139 (1956). Abstract A double cupferron separation of uranium using extraction
has been adapted to the micro level.
Uranium(VI) does not extract
in the first stage, which removes many potentially interfering elements.
Uranium(m),
obtained in the residual aqueous solution
by reduction at a mercury cathode, is simultaneously extracted as tie cupferrate Into ether, from which it can be re-extracted Into
297
PROCEDURE 12 (Continued) nitrio sold.
A relatively simple one-pleae glaea apparatus 18
used fo+ all opera$lone.
The
uraniumreaovery
at the mllligrem
level in an Inltlal 30-ml. sample was determined oolortmetrioally aB
9W.
With 0.03 to 0.13 T of radioactive uranium-233 traoer
and 20 y of natnral ursnlum as oarrier, the recovery IS 86j#; the latte~ includes the additional mtep of electrodepoeitlon of the uranium onto a platlnum planchet prior to measurement by alpha counting, whlah, la only 94$ oomplete. with
The deoontaminatlon possible
this proaedure was ohecked with 0.07 y quantities of uranlum-
233 In the Fesence reooverywas
of high mixed fls~ton produot actlvl,tie6; 8%
obtained’, aontaln%ng only 0.%
of the fission produat
alpha aotlvlty (assumed to be uranium). Apparatus The reaction cell and simple eleotrioal d.rcult used 1s shown In the accompanying figure. The electrolysis vesselP C, la proteoted tiom meroury ions dtffuslng from the working referenoe oalomel eleotrode, A, by a medtum glass frlt between B and Cp and a fine frit baoked with an agar plug between B and A.
Between runs, cell C Is kept f’llled
with Baturated potassium ohlorlde solution. The apparatus for the eleotrodepositlon of uranium onto platinum disks or planohets and for alpha-oountlng measurement of’the resulting uranium plates have been desoribed.-a
Beta
aotivity was measured by a ohlorlne-quenohed argon-filled (lelgerl&ller oounter (1.4 w.
per
sq.
om. of window) with a Model 165
sealer; a Bointlllatlon well aounter with a thalllum-aotivated eodlum Iodide wystal
and a Model 162 aoaler wm
actlvlty measurement of aolutlons x 150 mm. test tube.
(ea.
5 ml.)
used f’orgamma-
contained in a 13
The scalers and oounters are made by the
Nuclear Instrument and Chemloal Corp. gsmna-ray speotrum, a game-ray
For examination of the
solntlllatlon spectrometer (built
298
PROCEDURE 12 (Continued) in the Department of C,hcnnlstry,University of Michigan) wa~ u6ed
throqgh the courtesy of W. Wayne Melnke. Reagents All uhemlcals U8ed were of C.P. or reagent grade unles~ otherwise speolflied. The ethereal OUpferrOn solution used (200 to 300 mg. of cupferron per 50 ml.) was aatually a hydrogen oupferrate solutlon; the ether and oupferron were mixed in a mlxlng cylinder with 5 to 10 ml. of 10 to 2@
sulfuria aald and shaken
until dlS801ut10n was complete. PrOUOdUIâ&#x20AC;&#x2122;e8 Reduottve EKtraotion.
At the commencement of a run, bridge
B iS flushed through stopcook 2 by filling B with fresh potassium chlorlde solution from the funnel through 1.
C Is drained and
rinsed; 1 is left open for a time to flueh the frit. 4 to 5 ml.. of trlpledletllled
mercury
is
With 3 oloOed,
placed In C: About 30 ml.
of uranyl sulfate solution (0.5 to 5 mg. of uranium and 0.5 to 1.55 In sul.furlc acid) 18 added and a potential of -0.35 volt vs. S.C.E. IEIapplied to the mercurY. ether Cupferron 6olution LB added.
About 15 to 20 ~0
of the
Stirring 18 ad~usted at ~uflt
over the minimal rate for effl.cient ourrent flow (usually about 0.2 ma. flows without stirring and 1.2 to
2.6 ma. with stirring).
Stopaock 1 3.Bopened for about 30 seconds at approximately 5-lnute
Intervals throughout the run to mlnlmlze any 108s of
uranium into the bridge.
At 15- or 20-minute
lntervalB, stirring
IB interrupted, the ether extract is bled through ~topcock 4 lntO oell D, and 15 to 20 ml. of fresh ether-cupferron solution Im added. Runs of 40- to 55-minute total duration appem
to be adequate.
Three increments of ether-cupferron solution were usually used, followed by a 5- to 10-ml. pure ether rinse at the ooncluslon of â&#x20AC;&#x2DC;the run. (See Note 1.)
PROCEDURE 12 (Continued)
D
v
T
3
1.5
l%tmtio-
mehr
F 5
v.
-’ + ‘b Ion 3 v.
ELECTRICAL REDUCTION
C! RCUIT FOR ELECTROCHEMICAL OF URANIUM FOR Procedure 12.
Extraotlon and Measurement at Fllcrogram Urahtum Level. t331utlon Or uranium-233
A
(10-7 to 10-8 gram) together with about
20 y of natural uranium (as sulfate) wes submitted to reduotlve extraction with oupferron for about 50 to 60 minutes. uranium (~/111)
The
cupferrate was then re-extracted in oell D from
the ether Bolution into three auooeBaive 15-ml. portionk of 7~
300
PROCEDURE 12 (Continued) nltrlc acid.
The combined nitric acid extract was evaporated to
about 5 ml., treated with 25 to 30 ml. of concentrated nitric and 2 ml. of perchloric aoid, and then evaporated to dryne~e. reBidue wae digested with 10 ml. of O.l~nitrlc
The
aolcTâ&#x20AC;?for a few
minutes; the solution obtained, after addition of about 10,â&#x20AC;&#x2122;Ynmre of natural uranium (as sulfate), was used for electrodeposition of the uranium onto a platinum planchet from an oxalate msdium.~ A windowless flow counter with Q-gas was used for oountlng the alpha emission from the eleotrodeposited uranium.~ The whole operation took about 4 to 5 hours.
Eaoh measure-
ment of alphas from the samples waa calibrated by oountlng a uranium oxide standard (National Bureau of Standards No. 836-5). Note 1. In some runs the ourrent dropped to a low level soon after the requialte number of doulombs had pasmsd for about a 3electron reduction of the uranium present.
In obher oama,
the
current did not deareaae, but dlecontLnuance of the run beyond any point whtire twioe the theoretical our~ent had passed gave aatldactory
uranium recovery.
In the latter caseO* a gray
ether-
l.nOoluble, but alaohol-soluble prealpitate (apparently a merouq cupferrate)s waO usually evident in the aqueous plume.
The cur-
rent efficieflcy for the desired process appeared to be good in most runs. The aomblned ether extracts may be re-extraated in oell D by in8erting a olean stirrer, or they may be transferred with rlnalng Into a Glean separator ml. each of 0.5~
4%
funnel.
Three extraction
with 20 to 30
and 0.5~ nitrio acid were adquate
to re-
extract uranium Into aqueous solution.
Ac. L. RuMs,
A. K. De, P. J. Elving, J. Electroohem.Son. ~
80 (1957).
301
PROCEDURE 138 The Determination of Uranium by Solvent Extraction. Source: R. F. Clayton, Todd, Analyst=,
W. H. Eardwiok, M. Moreton-9mlth and R.
13 (1958). Abatraot
The development of aolventatraotlon
pkthodm for cleter-
mining traoe amounts of uranium-233 In Irradiated thorium 1s deacrlbed.
Thorium and its alpha-emlttlng daughters are com-
plexed with EDTA, and, when uranium-233 1s extracted as ltO diethyldlthlocarbamate
complex~ only blBmuth-212 accompanies it.
Thla 10 Immaterial fOr colorimetrio or flUOrlMetrlC
flnlahe~, but,
fâ&#x20AC;&#x2122;ordetermination of the urauium-233 by alpha oounting, the blmnuth-212 must first be allowed to decay.
If,
however, the
uranium-233 lm extracted qa lta 8-hydroxyqulnoline
oomplex~ no
alpha emitter aooompanlee it and ooncentratlon~ of uranium-233 ranging from 100 vg per ml down to 0.01 wg per ml in 0.7 ~ thorium solution have been determined in this way. KKCHOD FOR Dl?l!EtNININGURANIUM-233 ~
THOR~
NITRATE SOLUTIONS
BY EXTRACTION WITH OKDIE REAGENTS -Oxlne aolutlon A--A 10 per
oent w/v solution of 8-hydroxy-
qulnollne In isobutyl methyl ketone. Oxlne aolutlon B--A 2.5 per oent w/v solution of 8-hydroxyqulnollne in lBobutyl methyl ketone. EItCA BOIUtlOn--Dl80OlV0 372.9 g of the dleodlum salt of ethylenedlamlnetetra-acetfc
acid in 500 ml of water containing
80 g of aodi.umhydroxide and make up to 1 liter. 1 ml ~ 232 NltrLo
sold,
mg of
thorium.
~.
Ammonia aolutlon, BP. gr. 0.880. Ammonta solutlon, 0.2 ~. Bronmthynml blue Indioalzor solution. Anti-oreeplng aolutlon--A 20 per cent eolutlon
302
of ammonium
PROCEDURE 13 (Continued) ohlorlde containing 2 per cent of a water-soluble glue (Stephents Stefix wa8 found to be suitable). PROCEDURE FOR 0.01 TO 1 vg OF URANIUM-233 PER ml-Wlth a pipette place a suitable volume of sample solution, containing not more than 600 mg of thorium, in a 40-ml centrifuge tube fitted with a glaae stirrer.
Add ~A
Oolutlon to give about
a 10 per cent excess over the thorium equivalent and then add 3 drops of bromothymol blue indloator solution. Add ammonia solution, SP. w. turne blue.
0.880, until the indloator
Return the oolor of the indloator to yellow by adding
~ nitrio acid and then add 0.2 ~ ammonia solutlon until the oolor of the indicator Just turns back to blue (PH 7).
Add 2 id of
oxine aolutlon A, stir for 5 minutes, spin in a centrlf%ge to separate the phases and then stopper the tube. Evaporate dupllcate 0.25-ml portions of the solvent phase slowly on Htalnless-steel counting trays that have had 1 drop of anti-creeping solution evaporated at their centers.=
Heat the
trays to redness In the flame of a Meker burner, cool and count. PROCEDURE FOR 1 TC 100 ug OF URANIUM-233 PER ml-Wlth a pipette place a suitable volume of sample solutlon, containing about 10 pg of uranium-233, In a 40-ml oentrlfuge tube and dilute to 3 ml with water.
Add EDTA solution to give a 10
per cent excess over the thorium equivalent.
Add 2 drops of
bromothymol blue indicator solutton and adjuet the PH to 7 as previously desorlbed. Add 5 ml of oxlne solution B, stir for 5 minutes, apln In a centrifuge to separate the phases and then stopper the tube. Evaporate duplicate 0.1 or 0.25-ml portlona of the solvent phaae for counting, aa before. Note that for a fluorimetrlc fintsh to either procedures suitable dupllcate portlona of the solvent phase should be 303
PROCEDURE 13 (Continued) evaporated In platinum fluorlmeter dishes before tuslon with sodium fluoride. METHOD FOR DETERMINING URANIUM-233
IN THORIUM NITRATE SOLUTIONS
BY EXTRACTION WITH SODIUM D~HYLD~HIOCARBAMATE REAGENTS-Hexone. Sodium dlethyldtthlocarbamate
solutlon--A freshly prepared
and filtered 20 per oent w/v aqueous Dolution. EDTA solution--prepared as de~crlbed In reagents list, p. 377. Ammonium nitrate aolutton, 2 ~ . Ammonia solution, sp. gr. Q.880. Nitric acid, concentrated and ~. Screened methyl orange lndloator solutlon. Anti-creepln.g solutlon--A 20 per cent solution of ammonium chlorlde containing 1 per cent of a water-soluble glue. PROCEDURE FOR 1 TO 100 pg OF URANIUM-233 PER ml-Wlth a pipette place a suitable volume of sample solutlon~ containing about 10 vg of uranium-233, In a 40-ml centrifuge tube iâ&#x20AC;&#x2122;i.ttedwith a glaaa stirrer.
Dilute to 4-ml with 2 ~ auunoâ&#x20AC;&#x2122;nium
nLtrate and add lIDTA solutlon to gtve a 10 per cent excess over the thorium equivalent.
Stir end make just alkaline to screened
methyl orange by adding emmonla sodium dlethyldlthtocsrbamate
solution
and then add 0.5 ml of
solution.
Stir and add ~ nltrlo acid until the solution is mauve (not red) .
Add 5 ml of hexone, stir for 5 minutes and add more acid
to maintain the mauve color If necessary.
Spin In a centrifuge
to separate the phases and then stopper the tube. Evaporate aultable duplicate portions of the solvent phaae on atainle6s-steel counting trays that have had 1 drop of antlcreeping solution evaporated at their centers.
Heat the trayB
to rednese in the flame of a Meker burner, allow the bismuth-212 304
PROCEDURE 13 (Continued) to decay, and then count.
Alternatively, for a fluorimetrlo
flnlsh, evaporate duplluate Portlonm of’the solvent phase In platinum
fluortmeter dt~hes f’orfusion with sodium fluoride. Note that greater sensltlvlty oan be obtained by starting
with a larger volume of sample
or by evaporating larger portions
of the solvent phase. SW.
9 (1958).
H. Hardwtdr, M. Moreton-Smith, Analyst ~
PROCEDURE 14$
Uranium Radlochemical
Procedure Uned at the
University of California Radlatlon Laboratory at Llvermore. Source:
E. K. Hulet,
Deaontaminatlon:
UOIUI-4377 (1954).
3 x 1012 Atoms of $%
Isolated from a 3-dey14 fi8slons showed no old mixture oontalning 10 evidence of contamination when decay waa followed through three half lives.
Yield:
30 to 50 percent.
Separation time:
About four hours.
Reagents:
Dowex A-1 resin (fall rate of 5-30 cm/min). Zinc duBt, Isopropyl ether. 2~@(N03)2 2~HCl
1.
with ~HN03.
with 2~HF.
To the solution containing the actfvlty In HC1 in an Erlenmeyer flask , add uranium trauer in HC1, 1 ml of cone.
formia
acid and several ml of’ cone. HC1. 2.
Boil gently until volume is +-3
ml, replenishing the solu-
tlon with several ml of formic acid during the boiling. 3.
Transfer to 20-ml Lusterold centrifuge cone, rinsing flask twice with 1-2 ml of water and add 2-3 w
of La-.
ml of cone. H!?, stir, heat, and centrifuge.
305
Add 1
PROCEDURE 14 (Continued) 4.
Transfer supernatant to 20-ml Lusterold centrifuge cone, add 2-3 mg La-
5.
, Otir, heat, and centrifuge.
Transfer supernatati to 20-ml Lusterold, add 5-10 mg Is-, 1/2 ml of aona. HC1 and heat in a water bath.
When the solu-
tlon is hot, add small portions of zino dust and stir.
About
three small additions of zlno dust should be made over a haJ.fhour period with vigorous stirring after eaoh addition.
It
the zlno dust tende to ball and sink to the bottom of the tube at any times addition of’more cone. HC1 will solve this problem.
all the ztno from the laet addition has dissolved,
When
add 4 or 5 ml of water and 1 ml of cone.
HF.
centrifuge, retaining the LaF3 PreOIP1tate.
Stir,
aool, and
Wash precipitate
with 2 ml of 2M HC1 + 2M HF. 6.
Dissolve the precipitate with 6~ HN03 eaturated with H$03, stirring and heating.
‘l!ransi’er the eolution to a 40-ml glas”s
centrifuge cone, washing out the Lusteroid oone
7* Add several drops of ~02
and stir and heat.
with water.
Add 2 mg Fe-
and make solution baeic with NH40H and some NaOH. and centrifuge. 8.
Wash the precipitate with 2 ml of water.
Dissolve the precipitate in one to two drops of aonc. HN03 anti heat. ether.
9.
Heat, stir,
Cool, add 10 ml 2~Mg(N03)2
+ ~HN03
saturated with
Equilibrate twice with 10-15 ml of diisopropyl ether.
Pipet the ether phase Into a clean 40-ml cone and equilibrate ether layer with 3 ml ofooru. HC1. Pipet off and diecard ether layer.
Heat HC1 for
-30 seconds and again pipet off
the ether layer. 10.
Paes the HC1 solutlon through a Dowex-1 anion resin bed (2 om x 3 rmn) by pushing the solutlon through the oolumn with alr pressure.
Rinse the oentrTfuge tube onoe with 1 ml of
oonc. HC1 and pu~h this solution through the column. resin with -1 ml of cono.
HC1.
306
Disoard effluent.
Wash
PROCEDURE 14 (Continued)
11.
To column, add
-3/4 ml of 0.5~ HO1. Collect the eluate and
evaporate to a small volume and plate on a platinum dlsa.
PROCEDURE 15: Use of Ion Exchange Resins for the Determination of Uranium in Ores end Solutions. Source.
amd R. Kunln, Anal. Chem. ~,
S. Fhher
(1957).
400
Abstract The sep~atlon
of uranium from the Ions interfering with Its
analysls is accomplished by the adsorption of the uranium
sul-
fate complex on a quaternary annnonlum anion exchange re61n. ference of such ~ons
Inter-
as Iron(III) and vanadium(V) 1s avoided by
their pre~erential reduction with sulfurous acid so that they, as well as other cations, are not retained by the reein. eluted for analyela by dilute perchlorlo acid.
Uranium 1s
The method Is
applicable to both 8olutions and ores. Ore Solutlon TWO ~thods
for the operilng of uranium-bearing
ores
were
Investigated In con~unctlon with the Ion exchange separation.
The
first IB the standard digestion with hydrofluorlc and nltrtc aeld8, with subsequent evaporation to dryness followed by a sodium carbonate fuston.~
The carbonate melt Is dissolved in ~
acid to form a solutlon for the separation.
sulfuric
A second method for
routine analysls, designed to “eliminate the need for hood f’acillties and platlnum ves6el~, involves an oxldative leach with an acidic manganese(~) detail below.
oxide system.
Other worker~,
This procedure is glvbn,In
using the authorst separation
procedure, have recommended solution of the ore by treathent with 12~ hydrochloric aoid plus 16M nitric acid followed by fuming”
307
PROCEDURE 15 (Continued) with sulfurio sold to produce a Bultable urantum aolutlon for the column lnfluent. Frooedure.
Weigh out sem@les of ore estimated to contain
an amount ofâ&#x20AC;&#x2122;uranium oxide less than 100 mg. but sufficient to be detected by the chosen method of analysis.
Add 20 ml. of 2C@ by
voIume eulfurla acid and 2 grsme of manganese(~)
Heat
oxide.
Allow to cool to room temperature.
the mf.xture to boiling.
Dilute
AdJuet to a pH between 1.0
with approximately 50 ml. of water.
and 1.5 by the dropwise addttton of 2@
Filter
sodium hydroxide.
ttiough fine-pore filter paper using tyo 10-ml. portions of water to wash the residue on the paper. Ion ~ chawe Appar atus.
.
Separation
Tubes 0.5 Inoh In diameter with high-porosity
slntered glas~ filter disks fused to the lower end are used to contain the rbsinp
The rate of flow of solutions through the
tube is regulated by a screw clamp on rubber tubing below the flltsr.
Small aeparatory funnels are attached to the top of the
column to feed the sample and reagents. Prooedure.
Convert a portion ofâ&#x20AC;&#x2122;quaternary ammonium anion
exohange resin (Amberllte XE-117, Type 2) of mesh size 40 to 60 (U.S. soreens) to the sulfate formby l@
treatlnga
column of
sulfurto aold~ ueing 3 volumes per voluti of resin.
it with
Rinse the
acid-treated resin with delonlzed water until the effluent 16 neutral to methyl red.
Drain the resin eo prepared free of excess
water and store In a bottle. for a single anal$wls.
A
The realn
5-ml. portion of this resin 1s ueed Is
loaded Into the filter tube and
the bed so formed is backwashes with enough water to free It of air.
After the re~ln
has
settled
the
exces~
water
Is drained off
to wlthln 1 om. of the top of the bed prior to the passage of the sapple through the bed. Add 5 drops of 0.1$ methylene blue to the partially neu-
308
PROCEDURE 15 (Continued) trallzed (PH 1.0 to 1.5) solution from the dla~olved oodium oarbonate melt or from @
the
filtered manganese
oxide leaoh.
EIulfurouB aoid dropwiae until the -thylene
and then add a 5-ml. exoe8B. Pam
the
Add
blue is deoolorized
reduoed mmple ~
the
remin bed at a rate not exoeeding 2 ml. per minute. Waeh the EIemple oontalner mehlng
with two 10-ml. portions of water, passing the
through the re~lh bed at the sam flow rate. Elute the
uranium with 50 ml. of ~_ perohlorlo aoid. Determine the uranium oontent of the perchlorlo aoid ilmaotlonoolorimetrioallyby the Bk9tI&d
sodium hydroxide-hydrogenperoxide me.tho& or volumetri-
cally%
Rx
oolorismtrio analyoie
standard uranium solutions
oontainimg perohlorlo aoid should be ueed in establishing the ourve. =F.
9. GrImaldi, 1. MaY~ M. H. Fletoher, J. Titcomb, U. S. Oeol.
survey Bull. 1006 (1954). PH.
J. Seim, R. J. Morris, D. W. ~ew, U. S. Atomio Energy Cm.
Document UI&~-5
(1956).
~ O. J. Rodden, “Amalytlaal Chemistry of the Manhattan Mojeot,n MoGraw-Hill, New York, 1950.
PROCEDURE 16:
The Use of a “Compound” Column of Alumina and
CelluloEe for the Determination of Urenlum in Minerals and OreeI
Containing Ar6enio and Molybdenum. Souroe: W. Ryan and A. F. Hilliame, halyot~
293 (1952).
AbBtraot A technique In inorganic chromato~aphy, with eAunina and
oelluloBe adnorbenta In the Bame extraction column, In described for the separation of uranium
from
minerels
and ores. The pur-
pofleof the alumina is to retain amenic and nmlybdenum, tihh 309
PROCEDURE 16 (Continued) are not readily retained by cellulo8e alone when ether containing 5 per cent v/v of concentrated nttrl.c acid, sp.gr. 1.42, Is uBed as the extraotlon eolvent. METHOD FOR SAMPLES CONTAINING ~LYBDENUM
OR ARSENIC OR BOTH
Solvent--Add 5 ml of concentrated nitric acid, ap.gr, 1.42, to eaah 95 ml of ether. PREPARATION OF ALUMINA-CELLULOSE COLUMN-The adsorption tube for the preparation of the oolumn is a glaBa tube about 25 cm long and 1.8 cm In diameter.
The upper
end Is flered to a diameter of about 8 cm to form a funnel that permlta easy transfer of the sample.
The lower end terminates
In a Bhort length of’narrow tubing and ia closed by a ehort length of polyvlnyl chlorlde tubing carrying a screw clip.
The
inside surface of the glass tube is coated with a ~ilioone in the manner deeorlbed by Buratall and liellB.~ Weigh 5 or 6 g of cellulose pulp* into a Btoppered flask and
cover it with ether-nitric acid solvent. Pour the c!uspensloninto the glass tube, agitate gently and then gently press ”down the cellulose to form a homogeneous column.
Wash the column with
about 100’ml of ether-nltrio acid eolvent and finally allow the level of the solvent to fall to the top of the cellulose.
Next
pour about 15 g of aotivated alumintum oxide+ on top cifthe cellulose, pour on 30 ml. of orously,
~itate
ether-nitric acid solvent and
the alumina with a glass plunger.
packing to settle.
vig-
Allow the
Allow the level of the ether to fall to the
surface of the alumina and the column is ready for use.
*
Whatmanfs Standard Grade cellulose powder is suitable.
+ Type H, Chromatographlc Alumina, 200 mesh. Spence Ltd.
310
Supplied by Peker
PROCEIXJRE 16 (Cont~ed) PREPARATION OF S~
SOLUTION ~OH
~
OR OKB--
Wetgh Into a platinum dleh sufficient of the sample to give
100 to 150 mg of U3~, which IEIa convenient emunt ror a voluntric
determlnatton. Decompose the eample by treatment with
nitric and hytiofluorio acldaiIn the uanner demrlbed by Burntall and WellB.=
Finally remve
hydrofluorlo acid by repeated evapora-
tions with nltrlo acid and take the sample to ~eos. addition of dilute nltrlc
sold indicates the preeeme
If the of
undecom-
poeed material, f’llterthe insoluble reeidue on to a filter-paper and Ignite and fuse It In a niokel m’uolble wl~h a few pellet~ of potaselum hydroxide. Then add the melt to the filtrate and take the whole to drynemo.
Add 4 ml of diluted nltrlo sold, 25 per cent v/v, to the dry re~ldue, gently warm to dist301vethe mixture and then 0001 the Bolution, whioh 1s then ready i’orchromatography. KXTMOTION OF URANIUR!bansfer the sample on a wad of dry oelluloee pulp to the top of the prepared alumina-celluloseool~
and extract the
urenium with 200 to 250 ml of ether-nitric sold solvent If arsenic or molybdenum and emenlo
present in the original sample.
Is
If molybdenum alone IEIpresent, the amount of Eolvent can be reduced to 150 ml.
Screen the oolumn from dlreot sunlight. Ai%er
reumval of ether f’romthe eluate, determine the uranium volumetrically.= SF.
H. Bumatall, R. A. Wells, Analyst-
~F.
H. Bumtell,
A.
396 (1951).
“Hendbook Of Chemmal Methods
1?. William,
for the Determination of Uranium in Minerals end Oree,m H. M. Stationery Office, London, 1950.
311
PROOEDURE 17: Determlnatlon of Urenium-235 In Mixtures of Naturally Occurring Uranium IBotopea by Radloaotlvatlon. Source:
A. P. Seyfang and A. A. Smale8, Analyat~,
394 (1953).
Abatraot A method previously uae&
for determining
uranium In minerals
by neutron irradiation followed by measurement of the separated fission-product barium has been extended to the determination of uranium-235 In admixture with uranium-234 and uranium-238. With mlorogram annmnta of uranlumd35,
short Irradiations
In the Harwell pile give ample sensitivity. Preolslon and accuraoy of better than *2 per oent have been aohleved for a range of uranium-235 oontenta oovered by a faotor of more than 105. Method REAGENTS-Magnesium oxide--Analytioal reagent grade. Nltrlo aoid, sp. gr. 1.42. Barium chloride molutlon--Dtssolve 18 g of BaC12.2~0
in
water and nuke up to 500 ml.
Lanthanum nitrate solutlon--A 1 per
oent w/v solution of
6H20. ui(No3)3â&#x2014;? Amnonlum hydroxide, BP. gr. 0.880. Strontium carbonate solution--A 2 per cent w/v solutlon.
Hydrochloric aoid-diethyl ether reagent--A mixture of 5 part~ of oonoentrated hydroohlorlc acild,ap. gr. 1;18, and 1 part of
diethyl ether. Sodium tellurate solutlon--A 0.4 per oent w/v solutlon. Zlno metal powder. Methyl orange Lndioator. Potasalum Iodtde solutlon--A 1 per oent w/v solution. Sodium hypochlorlte solutlon--A amnmerolal aolutlon oontatning 10 per oent ofâ&#x20AC;&#x2122;available ohlorlne.
312
PROCEDURE 17 (Continued) Hydroxylamlne hydrochloride. Ferrlo Ohlorlde solution--A 1 per sent w/v aolutlon. Sulfuriu acid--A 20 per cent v/v ~olutlon. ~ADIATION-Sollda-- Samplen containing not much more uranium-235 than natural uranium
(say, up to three times more or 2 per cent) may
be irradiated as Bolid; tlilB
la Ueudly
U3080 For these Cut a
5-cm length of 2-mm polythene tubing and seal one end by warming
Introduce freshly ignited analytical reagent grade
and preeslng.
magnesium oxide to form a compact layer 4 to 5 mm In height at the eealed end of the tube.
Weigh the tube and aontent~, add
about 50 mg of U308 and re-weigh. Add a further similar layer of’_esium
oxide on top of the U308 and then seal the Open end.
Leave a free Bpaoe about 1 cm long between the top of the magnesium oxide layer and the seal,
f’or ease
of
opening. Treat
standard and samples similarly. Place the tubes either In a epecial polythene bottle for Irradlatlon In the pneumattc ‘rabbitn of the pile or In a 3-tnoh aluminum oan for Irradlatlon In”the ‘self-serve” holes h
the pile. Irradiation Is carried out for
any required the; usually It is about.5 minutes. After irradlattng, place the oontalners In lead ahtelding for about 15 hours.
After thiB period, tap down the oontents of the polythene
tube away from one end and oarefully out off the top.
contents into a 50-ml oxide
Bervea
to
‘rlnsen
centrifuge tube.
(The plug of
Empty the
magnestum
the sample tube as it Is emptied.) Add
2 ml of concentratednitric acid (sp.gr. 1.42), gently
warm to
dissolves and finally boll off the nitrous fumes. Add 5.00 ml of a barium solution to act as carrier (a solution of 18 g of barium chloride, BaClz “2~ O , In 500 ml of water). Llqulds--For more highly enriohed samples or when the amount of sample available Is small, solutlons containing weighed
313
PROCEDURE 17 (Continued) quantities of ~oltd sample must he irradiated in small ~lllca ampoules.
The ampouleB, whloh have a aapaclty of about 1 ml,
are @repared from
slllca tubing. After one end of eaoh has been
BealedP the ampouleB are weighed, the
sample solution added from
a fine-pointed glasa dropping-tube and the ampoules re-weighed. Pack the ampoules, after seallng the open ends, In cotton wool in a 3-inch alumintum can and irradiate them In the ‘self-serve” posltlon of the pile.
The time of trradiatlon neoesaary can be
calculated from the usual activation formula; as an example, 1 wg of Uranium-235 irradiated for 24 hours In a flux of 1012 neutrons per sq. cm per second gives about 5000 counts
per
minute
of barium-140 at 5 per oent counting efflclency, 24 hours after
the irradiation. After removing them from the pile,”place the samples and standards In lead ahleldlng for about 15 hours; the main actlvlty Is due to slllcon-31.
Transfer the ampoules
to
100-ml tall-form
beakers containing a few m~lllllters of water and 5.00 ml of’ barium aarrler solution, wu?efully break off both ends of each ampoule and warm to ensure thorough mlxlng.
Decant into centri-
fuge tubes and wash out the ampoules and beakers with further small portions of’water. CHEMICAL SEPAIblTION-Evaporate the solutlon containing the Irradiated uranium and barium oerrler to
5 to 6 ml and add two drops of 1 per cent
lanthanum nitrate solutlon.
Warm if necessary to dissolve any
barium nitrate that may have crystallized, add concentrated ammonium hydroxide dropwlse until a permanent precipitate Is obtatned and then two drops in exoess.
Into anotkr
centrifuge tube.
Centrifuge and decant
Add methyl orange Indicator, and
then hydrochloric sold until the solution 1s aoid. of 2 per cent
Add 2 drops
strontium solution, about 25 ml of hydrochloric
314
PROCEDURE 17 (Continued) acfd - diethyl ether reagent, mix thoroughly, centrifuge and
decant. Wash the preolpltate with 5 ml of reagent, centrifuge and deoant. Dissolve the barium chloride precipitate in 3 to 4 ml of water, re-precipitate It by adding 20 ml of reagent, centriWash with 5 ml of reagent, Centrlfige and decant.
fuge and deoant.
Dissolve the precipitate In about 5 ml of water , add 6 drops of lanthanum solution and 6 drops of the 4 per cent tellurate solution and then about 3 mg of zinc metal powder. When the effervescence ceases, make the solutlon Juet ammoniacal to methyl
orange, centrifuge and decant fnto another tube. Add 4 &OpS
Of
1 per cent potassium iodide solution and 2 drops of sodium hypo-
chlorite solution.
Warm and set aside for 2 minutes.
Acidify
with about 1 ml of hydrochloric acid, and add about 0.1 g of hydroxylamlne hydrochloride.
Boll under a hood until all the
Iodine appears to be removed and the volume 1s reduaed to
6 d.
5 to
Add 2 drops of strontium solution and 2 drops of lanthanum
solutlon and repeat the double barium chlorlde preclpltatlon and washlng~ as above. Dissolve the precipitate in about 5 ml of water, add 6 drops of lanthanum solutlon~ and 6 drops of 1 per cent ferrto chloride solution.
Make anwnlacal
to methyl orange, add half a orumbled
Whatman accelerator tablet, and heat just to bolllng.
Filter
through a 7-cm Whatman No. 30 filter-paper into a oentrlfuge tube, wash twloe with 2 to 3-ml portions of water.
Dilute the filtrate
to about 20 ml and make slightly acid with hydrochloric aoid. Heat nearly to bolllng and add dropwlse 2 nilof 20 per cent v/v sulfuric acid.
Allow the preolpitate to settle, decant, wash
with 10 ml of water, centrifuge, decant and repeat the washing procedure to complete removal of the excess of acid. T&ansfer as much as possible of the preclpltate, by means of a dropping tube and a few drops of water, to a tared alumlnium
315
PROCEDURE 17 (Continued)
counting tray.
Dry under an Infra-red lamp and finally heat in
A muffle furnaoe at 500â&#x20AC;?C for 15 minutes.
Cool, weigh and re-
serve for counting. COUNT~Ct TECHNIQUE-The oounting equipmnt Wwer
for thlt3work conslets of (1) a
unit (type 1082A or 200 is suitable), (11) Scaling unit
(type 2000r1009B),
(iii) time accessory unit (type 1003B),
(iv) probe unit (type 200Bor
1014A).
Time pulses oanbe
ob-
tained from a master eleotrlc olook serving several units.
A mloa
end-window (telger-~ller aounter (2 mg per sq. cm.)~ of type EHM2, is suitable; it Is nmunted In a lead oaetle with a Perspex lintng and shelves. Check the counting equipment In the normal fashion with a suitable beta-emltter$
rium with UXl and ~.
euoh as natural uranium oxide In equilibPlace the sample to be counted In a
Perspex carrier and tnsert It in a shelf at a suitable distance from the Geiger-~ller
tube to attain a counting rate of 2000 to
3000 oounts per minute.
Count for a suffloient time to obtain
at least 10,000 counts for each barium sulfate preoipltate~ countfng the preolpltates one after snother without undue delay. Correction for growth of lanthanum-lqO IB unneoeas~
If samples
and standsrds axe counted wlthln# say, 60 minutes of eaoh other provided the barium sulfate
preolpltatlons are carried out on
each nearly simultaneously. CALOUIATION OF RJISIILTS-Correct all aounta for background, ooinoldenoe loss and chemical yield and express
men
and
Wetght of$35 Weight ofU23~
In standard
Weight ofI#35
in sample
=
Weight ofâ&#x20AC;&#x2122; sample ~ .
aa the results In aounts per minute.
A. A. Smales, Analyst~,
Correated count of standard Correoted c!ountof sample
X 100 = percentage of uranium-23s. in sample.
778 (1952). 316
PROOEDURE 18: Determination of Mlorogram and Submiarogram Quantities of Umntum
by Neutron Activation AIMQ’BIB.
Source! H. A. Mahlman and G. W. Ledlcotte, Anal. Chem. 2&
823
(1955) . Abstraat Miorogram end submlcrogram quantities of uranium have been determined tn synthetlo samples, ores, and eoll~ by neutron
radloaotlvatlonanalyela. The prlnclplea of the aatlvatldn analysl~ method used in thisdeterminationand the prooeseing oi’ irradiated samples are discussed. This method of analysts la a sensitive and speoific method for determining uranium in concentrations as small as 0.1 T per gram with a probable relative standard error of I@.
Concentrations of uranium in quantitieO
as small aa 0.0001 y per gram oan be determined by neutron aoti~ atlw
analysis.
Radioactivation Analyaia of Samplea that Contain Uranium Nuclear Irradiation of’Sample.
Weighed portions of the
samples and the comparative standard are put Into mall quartz tubes. The tubes are closed with cork stoppers that are wrapped in aluminum. They axe then irradiated in the reactor.
After
Irradiation, the samples are allowed to deoay about 4 hours and are then chemically prooeased as described below.
The synthetio
samplea used in this laboratory had been processed by a paper partition chromatography teahnlque.
filter
After the separation,
the paper was conveniently irradiated 10 short pieoea of quartz tubing whose openings were plugged by means of cork stoppers. Chemical Separation of Neptunium-239.
In most neutron
activation analyse8, a chemical separation is made to isolate the radioactivity of the element from all other radioactive species in the sample.
Usually an “isotopic carriern--a known
amount of the natural inactive element--is added to the solutlons
317
PROCEDURE 18 (Continued) of both the irradiated specimen and the compsri.son samples.
The
solutlons axe then processed chemically to Isolate the carrier and deOired radloelement from other elements and contaminant radioactlvltles.
Small amunte
of other element~ are added as
holdback or soavenglng uarrlers to assist in the de~onte,minatlon process. Although neptunium-239 has,a oonvenlent half life, it does not have a stable Isotope that can be used as anâ&#x20AC;&#x2122;lsotoplc csrrier. However, Seabor&
has shown that trace quantities of neptunlum-
239 can be quantitatively carried on a nonlsotoplo carrier, such as cerlum.
The method of analysls reported below uses lanthanum
as a nonlsotopic carrier for the neptunium-239 radioactivity. (See Note 1.) Chemical Separation Procedure.
PREPARATION.
The Irradiated
ore and SO1l specimens are dissolved by dlgestlon in a mixture of concentrated nttrlc, hydrofluorlc# perahlorlc, and sulfuric acids.
(Additional hydrofluorlc acid can be added if a residue
of silica remains In the bottom of the crucible.)
After dissolu-
tion, the sample Is concentrated to heavy sulfurfc acid fumes, cooled, and transferred to a 15-ml. centrifuge tube.
If a residue
(sulfate salts) remains after the transfer. the solution IS centrifuged for 5 minutes. the supernatant transferred to another tube, and the residue washed with 1 ml. of 1~ nttrlc aol.d. The wash Is added to the supernatant and the residue discarded. (Centrlfugation is always forthe speed.)
stipulated time and at full
The sample Is then further prooessed by the procedure
reported herein. The irradiated synthetlo samples (paper chromatograms) are processed by carefully igniting the paper contained In a porcelain crucible In a muffle furnace.
The residue Is dissolved in about
0.5 ml. of concentrated nitric acid.
318
After dlssolutlon, the
PROCEDURE 18 (Continued) sample La tranafemed
to a 15-ml. centrifuge tube and the process-
ing continued with the procedure reported herein.
PROCEDURE . Three (3.0) milligrams of lanthanum and 0.250 ml. of 5~hydroxylamlne
hydrochloride solution are added to the
supernatant solutlon and the mtiture dlgeOted for 5 mlnute6 with occasional stlrrlng.
The solution Is oautiâ&#x20AC;&#x2122;oualy neutralized with
concentrated ammonium hydroxide to precipitate lanthanum hydroxide, after which the mixture Is centrifuged and the supernatant liquid discarded. The precipitate of lanthanum hydroxide Is dissolved in 2 ml. of 2~ hydroohlorlc acid, and 1.0 mg. of strontium (added as a solutton of stronttum nitrate to serve as a holdback or soavenglng carrier) and 0.250 ml. of 5~ hydroxylamine hydrochloride solution are added to the solution.
The solutlon is again digested for
5 minutes with intermittent stirring, and 0.200 ml. of concentrated hydrofluorlo acid Is added dropwlae to the solutlon to prealpltate lanthanum fluoride.
After centri.fugation, the supernatant llquld
is discarded and the precipitate washed with 0.5 ml. of ~hydrofluoric acid-1~ nitric acid solution. After washing, the lanthanum fluoride precipitate is dissolve~ in 0.5 ml. of saturated boric acid solution and 1.0 ml. of 6~ nitrtc acid.
One (1.0) milliliter each of l@
potassium perman-
ganate solution and water are added to this solution, and the resulting mixture is agitated well and digested for 5 minutes. Lanthanum fluoride is again precipitated with 0.250 ml. of concentrated hydrofluoric acid; the solution is centrifuged and the supernatant liquid transferred to another centrifuge tube. precipitate is washed with 0.5 ml. of 1~ hydrofluoric acid-~
The nitric
acid solution and the wash combined with the.aupernatant llquld. The precipitate is discarded. Three milligrams of lanthanum are added to the supernatant
319
â&#x20AC;&#x153;
PROCEDURE 18 (Continued) liquid, and the aolutlon la digested for 5 mlnutea
and centrifuged.
An addlttonal 3.0 mg. of lanthanum are added to the supernatamt llquld and the aolutton agitated and digested for 5 minutes without disturbing the first precipitate on the bottom of the tube; then the solutlon Is centrifuged and the supernatant liquld tranBferFed to another centrifuge tube. ml. of l~hydrofluorlc
The p??ecipltate i.awashed with 0.5
acid-l! nltrlc aotd solutlon; centrifuged, The precipi-
and the wash oomblned with the eupernatant liquld. tate is dleoarded.
One milllgram of zirconium (added as a solution of zlrconlum nitrate to serve a~ a holdback or soavengimg carrier) and 0.250 ml. of 5% hydroxylamlne hydrochloride are added to the aolutlon and Three (3.0) milli-
the mixture agitated and digested 5 minutes. grams of lanthanum and 2 ml. of 2~hydrofluorlc
aoid are added
to the solution, and the solutton Is digested for 20 minutes and then centrifuged.
The supernatant llquld 1s discarded.
The pre-
cipitate Is washed with 0.5 ml. of ~_ hydrofluorlo acid-1~ nitric acid solutlon, and the reaultlng mixture Is centrifuged.
The
wash solution is discarded after the uentrifugation. The precipitate 1s ~lurrled in a small amount of ~
nitr~o
acid (about 0.5 ml.) and transferred to a small borosilicate glaas culture tube by means of a tranafâ&#x20AC;&#x2122;er pipet.
The centrifuge cone aoid and the
Is rinsed with three 0.5-ml. portions of
l~nitric
rinses transferred to the oulture tube.
The tube is stoppered
with a cork stoppep and the Y radloaotivlty measured by a welltype gamma acintill,ation counter. The standard sample of uranium oxide (U308) Is dissolved in nitric aQtd and an aliquot of the aolutlon processed under the same oondltions as the speoi~n
samples.
The uranium aontent
of the sample In question la determined by equating the ratio of --the corrected neptunium-23$1 radioactivity count in the unknown
320
PROCEDURE 18 (Continued) and the corrected neptunium-239 radioactivity count in the standard sample. Note 1.
Hamaguchl and co-worker~
have ueed Np237 tracer
to determine the chemical yield..
~ G. T. Seaborg and co-workers, Metallurgical FYoject Rept. CN2689,41 (Feb. 15, 1945) (classified). Geochim. et Cownochlm. ~ H. Hamaguohl, G. W. Reed, A. !l?urkevt.ch, Acta12,
337 (1957).
Acknowledgements It 1s a pleasure to acknowledge the assistance of Miss M. Tippet, Miss R. Cushing, Mr. N. Zaichlok and others of the Argonne National Laboratory library staff in
locating
the many
references used In writing this paper; Dr. E. K. Hyde, who kindly made available his file on the radioohemistry of urantum; Mrg. D. E. Williams, who typed most of the manuscript; Miss F. Taylor, for preparing the final figures; Dr. C. E. Crouthemel, who furnished the figures of gannna-ray spectra; Dr. D. W. Engelkemeir and Mr. D. J. Henderson, who supplied the data for the alpha spectra; and finally, Miss B. Lore and Mr. C. Ahlberg, without whom the completion of this paper would have been much, much later.
321
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1958. 615. H. P. Raaen, l?.F. ‘lhomaaon~ Anal. Chem. ~, 616. F. H. Buratall, R. A. Wells, Analyst ~, 617. W. Ryan, A. F. wllliams, Analyat~, 618. E. Haeffner, A. Hult~en,
936 (1955).
396 (1951).
293 (1952).
Nuclear Sci. & Eng. ~
471 (1958).
619. A. Hultgren, E.Haeffner, P/144, Froceed. Internat. Conf. Peaceful Usea Atomic Energy, Geneva, 1958,q, 324 (1958). 620. J. Kennedy, F. A. Buford, P. G. Sammes, J. Inorg. Nuclear Chem. lJ-114
(196o).
621. H. Small, J. Inorg. Nuclear Chem. I-8, 232 (1961). 622. H. H. Hymn,
R. C. Vogel, J. J. Katz, Progress in Nuclear Energy, Series III, l-, 261 (1956).
623. c. c. Caato, “Analytical Chemistry of the Manhattan Pro.jeat,n NNEs,
Dlvls~on VIII, Volume 1, C~pter
23.
624. E. F. Smith, Chem. Ber. I-Q, 751 (1880). 625. E. F. Smith, D. L. Wallace, J. Am. Chem. Sot. 2Q, 279 (1898). 626. L. G. Kollock, E. F. Smith, J. Am. Chem. Sot. ~,
607 (1901).
627. R. Coomana, Ing. Chlm. 10, 213 (1926). 628. B. Cohen, D. E. Hull, MDm-387 629. O. A. Cook, TID+290
(1946).
(1958), Paper 18, p. 147.
630. A. Brodsky, L. W. Flagg, T. D. Hanacome, NRL-4746 (1956). 631. P. I. Chalov, Trudy Inst. Geol. Akad. Nauk Klrglz. SSR, No. 9, 231 (1957); N. S. A. ~,
10991 (1959).
632. R. W. Dodson, A. C. Graves, L. HelmholZ, D. L. Hufford, R. M. Potter, J. G. Povelltea, “Miscellaneous physical & Chemical Techniques of the Los Almnos Project,” NNES(1952), Division V, Volume 3, Chapter 1.
633. L. Koch, J. Nuclear Energy ~, 110 (1955). 634. C. Rulfs, A. K. De, P. J. Elvlng, Electrochem. Sot. ~, ( 1957)
~
3’47
80
635. C. McAulifi’e,A-3626 636. G. I. Khlebnikov
(1946).
E. P. Dergunov, Atocmaya Energ. ~, 376
(1958); AEC-tr-3!n.
637. ~. Whltson,T. KwaHnoskl, K-1101 (1954). 638. C. R. Wilson, A. Langer, NucleonIce 11, Nb. 8, 48 (1953). 639. R.
Ko,
ltucleonics~
No. 1, 72 (1957).
640. I. Alter, E. Foa, Y. Marcus, J. Trocker A. Gruenstein, J. Lavl, I. Prulov, J. Tulipman, A. Waldmn, P/1~09, Proceed. Internat. Conf. Peacefil Uses Atomic Energy, Geneva, 1958, ~ 268 (1958). 641. M. I@hn,
MDDC-1605 (1943).
642. R. F. Mitchell, Anal. Chem. ~
326 (1960). Series III, g, 35 (1958).
643. R. Kunin, Progxess in Nuclear Energy,
644. H. H. Willard, J. J. Finley, K-1219 (1956). 645.
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646. E. P. Steinberg, AFL-6361 (1961). 647. Q. C. Hanna, ‘ExperimentalNuclear PhySlCE,u Volume III, Part IX, John Wiley& SonB, New York, 1959. 648. M. Deutsch, O. Kof’06d-Hansen, “Experimental Nucleer Physio13,” Volume III, Parta X and XI, John Wiley & Sons, New York, 1959.
649. C. E. Crouthamel, ‘A lled knmna-llaySpectrometry,n Pergamn PreBs, New York, 1& .
650.
“The Actinide Elements,” NNES, Division Iv, 16 (1954).
%l&eJ$~6hapter
651. D. Strounniner J. M. Hollander, G. T. Seaborg, Revs; Modern WE.
3
*
fl~8)=
652. W. Meinke, Anal. Chem. ~ 104R (l$t60).
736 (1956);~
686 (1958);~
653. D. L. Hui’ford, B. F. Scott, ‘The Traneuranium Elements 9 NNES, Division IV, Volume 14B, Paper 16.1, p. 1149 (19$9). 654. H. A. C. MoKay, 287 (1955). 655. B. B. Rossl, NNES, Division
H.
J.
MllBted,
Pro~erJs
in
Nucleer
Phyoics
H. Staub, W1onLzatiOn ChamberB and COUnterEi#” V, Volum 2, p. 210 (1949).
656. K. M. (hover, P. Borrell, J. Nucle= Energy~ 657. F.
Asaro,
~
I. Perlrnan,PhyB. Rev. ~318
658. J. R. Huizenga, C. L. Rae, D.
214 (1955).
(1957).
W. Engelkemir,
Phye. Rev. ~,
319 (1957). Energy~ 659. D. J. Cerawell, J. Milsted, J. .J?uclear
51 (1957).
660. D. J. Hughes, R. B. Schwartz, BILL-325,Semnd Edition (1958). 348
661. J. D. Phi@t,
R. K. Smith, B. Warren, Phys. Rev. ~
259 (1958).
662. W. H. Wade, J. Gonzalez-Vldal, R. A. Glaas, G. T. Seaborg, , 1311 (1957).
663. W. W. T. Crane, G. M. Iddings, MTA-48 (1953). 664. J. Wing Rev. ~,
W. J...Ramler, A. L. Harkness, J. R. Huizenga, Phys. 163 (1959).
665. L. M. Slater, UCRL-2441 (1954). 6660 R. M. Lessler, UCRL-371O (1957), P. 8’7. 667. B. M. Foreman, Jr., W. M. Gibson, R. A. Glass, (?.T. Seaborg, Phys. Rev. 116, 382 (1959).
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1358 (1958).
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1042 (1953).
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5577 (1956). 15669 (1960).
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2501
(1960) .
681. L. A. Slotin, U. S. Patent 2,823,977 (1958); NSAI-2, 10243 (1958) .
682. R. P. Larsen, Anal. Chem. ~,
545 (1959).
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349
687. L. Warf, CC-1194 (1943).
688. H. M. Feder~ R. P. Larsen, M. Beederman, H. E. 5103 (1953).
EVSIIB,
A?L-
689. BNL-583 (1959); NSAIQ, 17642 (1960).
690. W. Sborgl, Z. Elektrochem. ~,
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69I.. J. A. McLaren, D. W. Cllne, H. S. Cllnton
J. J. Finley, J. H. Goode, J. A. Westbrook, K-587 (1950~.
6%”
M. Kolodney, U. S. Patent 2,872,387 (1959); NSA ~ (1959).
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9444 (1960).
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13320
W.
Clegg,
(1950).
6950 E. W. Chrlsto herson, H. R. Gra AECD-4181 (19g6); NSA~,
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350
.
NUCLEAR SCIENCE SERIES: MONOGRAPHS ON RADIOCHEMISTRY AND RADIOCHEMICAL TECHNIQUES See the back of the title page for availability
Silimn, NAS-NS-3049
ELEMENTS
SiiVer,
Aluminum end Gallium, NAS-NS-3~2 Americium and Curium, NAS-NS-3006 Antimony, NAS-NS-3033 [1651] Araanic, NAS-NS-3002 [Rev.) [19651 Aatadrre, NAS-NS-3012 [19601 Barium, Calcium, end Strontium,
NAS-NS-3005
Sodium, NAS-NS-3055
16601
Sutfur, NAS-N~
Thorium, NAS-NS-3004 Tin, NAS-NS-3023
Lead, NAS-NS-3040 Magn~ium,
NAS-NS-3042
[1661]
Uranium, NAS-NS-3050
[1961]
Vanadium, NAS-NS-3022 Zinc, NAS-NS-3015
TECHNIQUES
NAS-NS-311O
[1%11
Radi-hemical [1962]
Liquid-Liquid
[1%2] I
Polonium, NAS-N%3037
[19611
Pota*um,
[1%11
Protactinium, NA%NS-3016
in Radio [1S67]
NAS-NS-311X
[1661 ]
Extraction with High-
[19601 Low-Laval Radiochernid NAS-NS-31
Seperatiorra,
m [1661]
Paper Chromatogrephic and Eltiomi~tion
[13591
T*rriqu~
[19641
Rare Eartha-scandium,
NAS-NS-3111
Molecular-Weight Amim,NAS-NS-3101
1
[1965]
NA%NS-3048
&rarni*, Radiatim,
[16611 [1*
[19611
[1971]
Yield De~rrninati~
Detectiorr and Measurement of Nuclear
[16611
Plutonium, NAS-NS-3056
Separationa,NAS-NS-3106
them-ktry, NAS-NS3113 Chemial
Niobium and Tantalum, NAS-NS-3039
Phasphorua, NAS-NS-3E6
[ 1=2]
Cetion-Exchanga Techniques in Radio-
[1s601
[19611
Radium, NAS-NS-3057
[1666]
of Computere to Nuclear and
(RwJ.)[19711
(Rav.) [1970]
Platinum, NAS-NS-3044
Maawrament of Alpha Emieakm
Radiochemiaby, NAS-NS-3107
Palladium, NAS-NS-3052
[1660]
Application af Diatillatiofr Techniques to
NAS-NS-3009
Osmium, NAS-NS-3046
[1660]
[1660]
Zircomium and Hefnium,NAS-NS3011
Applicaiiom
[19611
NAS-NS-3024
[1660]
[19661
[lWOI
Mercury, NAS-N$3026
(Rev.) [1971]
Elemerm, NAS-NS-3031
Activation Analyeia with Charged Partiol-,
[lHO]
Nickel, NAS-NS-3051
Turr~rr,
[1660]
and Spontaneous F-&icm, NAS-NS-3112
[19611
Manganeae, NAS-NS-3018 Molybdenum,
Tran=urium
[1960]
[19601
Titanium, NAS-NS-3034
Ahluta [1960]
Iridium, NAS-NS-3(.M5 [1961] Iron, NAS-NS-3017
[1960]
Tellurium, NAS-NS3036
Germanium, NAS-NS-3043, [19611 Iridium, NAS-NS-3014
[1962] [1=1]
Technetium, NASW&3021
[19601
Gold, NAS-NS-3036
[Rev.) [196S] [ 16611
NAS-NS-3047
1961]
NAS-NS-301O [1960] Beryllium, NAS-NS-3013 [1960] Cadmium, NAS-NS-3~1 [1960] Carbon, Nitrogan, and Oxygen, NAS-NS-3019 [19s01 Caaium, NAS-NS-3035 [19611 Chromium, NAS-NS-3007 (Rev.) [1953] cobalt, NAS-NS-3041 [13611 Copper, NASN%3027 [lWI 1 Fluorine, Chlorine, Bromine, end Iodine, Frencium, NAS41S-3003
information
Yttrium, ad
31K
in Radimhemkrtry, NAS-NS
[1 SM321
Actinium, NAS-NS-3020
[1661]
Procarsirrgof Counting Date, NAS-N&3109
Rare Gtmaa,NAS-NS-3026
[16601
[1 6651 Rapid Radi~emical Saparatiom, NAS-NS 3104 [19611 Sepamtiona by Salvunt Extraction with Tri+r-atylphaphina Oxida, NAS-NS-3102
Rhenium, NAS-NS~026
[19611
Rhodium, NAS-NS-3006
(Rev.) [1 ml
Rubidium, NAS-NS-3053
[1=2]
Ruthenium, NAS-NS-30ZB Selenium, NAS-NS-3030
[19S11
(Rev.) [1665]
[19611
Current as of January 1972
F?adiochernist.ry of Uraniuâ&#x20AC;&#x2122;rn
NAWW-3050
USAEC